Application of cutting fluids in machining processes

In the last decade a lot has been discussed about the suitability of using cutting fluid in abundance to cool and lubricate machining processes. The use of cutting fluid generally causes economy of tools and it becomes easier to keep tight tolerances and to maintain workpiece surface properties without damages. In the other hand, it brings also some problems, like fluid residuals and human diseases. Because of them some alternatives has been sought to minimise or even avoid the use of cutting fluid in machining operations. Some of these alternatives are dry cutting and cutting with minimum quantity of fluid (MQF). The main goal of this work is to discuss these tendencies. Therefore, topics like kinds and methods of applications of modern cutting fluids and what are new in this area will unavoidably be considered. MQF and dry cutting techniques, their applications and where it is not possible to apply them will also be focused. To exemplify the topics, this work will describe some of the researches been developed in two important Brazilian Universities: State University of Campinas (UNICAMP) and Federal University of Uberlândia (UFU).

Minimum detection limit of an in-house nested-PCR assay for herpes simplex virus and varicella zoster virus

Introduction Herpes simplex virus (HSV) and varicella zoster virus (VZV) are responsible for a variety of human diseases, including central nervous system diseases. The use of polymerase chain reaction (PCR) techniques on cerebrospinal fluid samples has allowed the detection of viral DNA with high sensitivity and specificity. Methods Serial dilutions of quantified commercial controls of each virus were subjected to an in-house nested-PCR technique. Results The minimum detection limits for HSV and VZV were 5 and 10 copies/µL, respectively. Conclusions The detection limit of nested-PCR for HSV and VZV in this study was similar to the limits found in previous studies.

A determinação dos números de indivíduos mínimos necessários na experimentação genética

The main object of the present paper consists in giving formulas and methods which enable us to determine the minimum number of repetitions or of individuals necessary to garantee some extent the success of an experiment. The theoretical basis of all processes consists essentially in the following. Knowing the frequency of the desired p and of the non desired ovents q we may calculate the frequency of all possi- ble combinations, to be expected in n repetitions, by expanding the binomium (p-+q)n. Determining which of these combinations we want to avoid we calculate their total frequency, selecting the value of the exponent n of the binomium in such a way that this total frequency is equal or smaller than the accepted limit of precision n/pª{ 1/n1 (q/p)n + 1/(n-1)| (q/p)n-1 + 1/ 2!(n-2)| (q/p)n-2 + 1/3(n-3) (q/p)n-3... < Plim - -(1b) There does not exist an absolute limit of precision since its value depends not only upon psychological factors in our judgement, but is at the same sime a function of the number of repetitions For this reasen y have proposed (1,56) two relative values, one equal to 1-5n as the lowest value of probability and the other equal to 1-10n as the highest value of improbability, leaving between them what may be called the "region of doubt However these formulas cannot be applied in our case since this number n is just the unknown quantity. Thus we have to use, instead of the more exact values of these two formulas, the conventional limits of P.lim equal to 0,05 (Precision 5%), equal to 0,01 (Precision 1%, and to 0,001 (Precision P, 1%). The binominal formula as explained above (cf. formula 1, pg. 85), however is of rather limited applicability owing to the excessive calculus necessary, and we have thus to procure approximations as substitutes. We may use, without loss of precision, the following approximations: a) The normal or Gaussean distribution when the expected frequency p has any value between 0,1 and 0,9, and when n is at least superior to ten. b) The Poisson distribution when the expected frequecy p is smaller than 0,1. Tables V to VII show for some special cases that these approximations are very satisfactory. The praticai solution of the following problems, stated in the introduction can now be given: A) What is the minimum number of repititions necessary in order to avoid that any one of a treatments, varieties etc. may be accidentally always the best, on the best and second best, or the first, second, and third best or finally one of the n beat treatments, varieties etc. Using the first term of the binomium, we have the following equation for n: n = log Riim / log (m:) = log Riim / log.m - log a --------------(5) B) What is the minimun number of individuals necessary in 01der that a ceratin type, expected with the frequency p, may appaer at least in one, two, three or a=m+1 individuals. 1) For p between 0,1 and 0,9 and using the Gaussean approximation we have: on - ó. p (1-p) n - a -1.m b= δ. 1-p /p e c = m/p } -------------------(7) n = b + b² + 4 c/ 2 n´ = 1/p n cor = n + n' ---------- (8) We have to use the correction n' when p has a value between 0,25 and 0,75. The greek letters delta represents in the present esse the unilateral limits of the Gaussean distribution for the three conventional limits of precision : 1,64; 2,33; and 3,09 respectively. h we are only interested in having at least one individual, and m becomes equal to zero, the formula reduces to : c= m/p o para a = 1 a = { b + b²}² = b² = δ2 1- p /p }-----------------(9) n = 1/p n (cor) = n + n´ 2) If p is smaller than 0,1 we may use table 1 in order to find the mean m of a Poisson distribution and determine. n = m: p C) Which is the minimun number of individuals necessary for distinguishing two frequencies p1 and p2? 1) When pl and p2 are values between 0,1 and 0,9 we have: n = { δ p1 ( 1-pi) + p2) / p2 (1 - p2) n= 1/p1-p2 }------------ (13) n (cor) We have again to use the unilateral limits of the Gaussean distribution. The correction n' should be used if at least one of the valors pl or p2 has a value between 0,25 and 0,75. A more complicated formula may be used in cases where whe want to increase the precision : n (p1 - p2) δ { p1 (1- p2 ) / n= m δ = δ p1 ( 1 - p1) + p2 ( 1 - p2) c= m / p1 - p2 n = { b2 + 4 4 c }2 }--------- (14) n = 1/ p1 - p2 2) When both pl and p2 are smaller than 0,1 we determine the quocient (pl-r-p2) and procure the corresponding number m2 of a Poisson distribution in table 2. The value n is found by the equation : n = mg /p2 ------------- (15) D) What is the minimun number necessary for distinguishing three or more frequencies, p2 p1 p3. If the frequecies pl p2 p3 are values between 0,1 e 0,9 we have to solve the individual equations and sue the higest value of n thus determined : n 1.2 = {δ p1 (1 - p1) / p1 - p2 }² = Fiim n 1.2 = { δ p1 ( 1 - p1) + p1 ( 1 - p1) }² } -- (16) Delta represents now the bilateral limits of the : Gaussean distrioution : 1,96-2,58-3,29. 2) No table was prepared for the relatively rare cases of a comparison of threes or more frequencies below 0,1 and in such cases extremely high numbers would be required. E) A process is given which serves to solve two problemr of informatory nature : a) if a special type appears in n individuals with a frequency p(obs), what may be the corresponding ideal value of p(esp), or; b) if we study samples of n in diviuals and expect a certain type with a frequency p(esp) what may be the extreme limits of p(obs) in individual farmlies ? I.) If we are dealing with values between 0,1 and 0,9 we may use table 3. To solve the first question we select the respective horizontal line for p(obs) and determine which column corresponds to our value of n and find the respective value of p(esp) by interpolating between columns. In order to solve the second problem we start with the respective column for p(esp) and find the horizontal line for the given value of n either diretly or by approximation and by interpolation. 2) For frequencies smaller than 0,1 we have to use table 4 and transform the fractions p(esp) and p(obs) in numbers of Poisson series by multiplication with n. Tn order to solve the first broblem, we verify in which line the lower Poisson limit is equal to m(obs) and transform the corresponding value of m into frequecy p(esp) by dividing through n. The observed frequency may thus be a chance deviate of any value between 0,0... and the values given by dividing the value of m in the table by n. In the second case we transform first the expectation p(esp) into a value of m and procure in the horizontal line, corresponding to m(esp) the extreme values om m which than must be transformed, by dividing through n into values of p(obs). F) Partial and progressive tests may be recomended in all cases where there is lack of material or where the loss of time is less importent than the cost of large scale experiments since in many cases the minimun number necessary to garantee the results within the limits of precision is rather large. One should not forget that the minimun number really represents at the same time a maximun number, necessary only if one takes into consideration essentially the disfavorable variations, but smaller numbers may frequently already satisfactory results. For instance, by definition, we know that a frequecy of p means that we expect one individual in every total o(f1-p). If there were no chance variations, this number (1- p) will be suficient. and if there were favorable variations a smaller number still may yield one individual of the desired type. r.nus trusting to luck, one may start the experiment with numbers, smaller than the minimun calculated according to the formulas given above, and increase the total untill the desired result is obtained and this may well b ebefore the "minimum number" is reached. Some concrete examples of this partial or progressive procedure are given from our genetical experiments with maize.

Antibodies in falciparum malaria: what matters most, quantity or quality?

In view of the recent demonstration that antibodies that are protective agains Plasmodium falciparum malaria may act in collaboration with blood monocytes, we have investigated the isotype content of sera from individuals with defined clinical states of resistance or susceptibility to malaria. Profound differences in the distribution of each Ig subclass and particulary in the ratio of cytophilic versus noncytophilic antibodies were found. In protected subjects, two cytophilic isotypes, IgG1 and IgG3 were found to predominate. In non-protected subjects, i.e. children and primary attack adults, three different situations were encountered: a) an imbalance in which IgG2, a non-cytophilic class, predominated (mostly seen in primary attacks); b) imbalance in which mostly IgM antibodies predominated (a frequent event in children) or c) less frequently, an overall low level of antimalarial antibodies. Of 33 non immune subjects studied all, except one, had one of the above defects. The function of total Ig presenting such an isotype imbalance was studied in vitro in Antibody-Dependent -Cellular-Inhibition assays. Not only did IgG from protected subjects cooperate efficiently with blood monocytes, whilst IgG from non-protected groups did not, but moreover the latter inhibit the in vitro effect of the former: in competition assays whole IgG from primary attack cases with increased IgG2 content, competed with IgG from immune adults, thus suggesting that non-protected subjects had antibodies to epitopes critical for protection, but that these antibodies are non functional.

Slime production and proteinase activity of Candida species isolated from blood samples and the comparison of these activities with minimum inhibitory concentration values of antifungal agents

Slime and proteinase activity of 54 strains consisting of 19 Candida parapsilosis and 35 C. albicans strains isolated from blood samples were investigated in this study. Ketoconazole, amphothericin B, and fluconazole susceptibility of Candida species were compared with slime production and proteinase activity of these species. For both Candida species, no correlation was detected between the slime activity and minimum inhibitory concentration (MIC) values of the three antifungal agents. For both Candida species no correlation was detected between the proteinase activity and the MIC values of amphothericin B, and fluconazole however, statistically significant difference, was determined between the proteinase activity and MIC values of ketoconazole (p = 0.007). Slime production was determined by using modified Christensen macrotube method and proteinase activity was measured by the method of Staib. Antifungal susceptibility was determined through the guidelines of National Committee for Laboratory Standards (NCCLS M27-A).

Attaining the minimum target of resolution WHA 54.19 for schistosomiasis control in the Rainforest Zone of the state of Pernambuco, Northeastern Brazil

Resolution 19 of the 54th World Health Assembly (WHA-54.19) urged member nations to promote preventive measures, ensure treatment and mobilize resources for control of schistosomiasis and soil-transmitted helminthiases (STH). The minimum target is to attend 75% of all school-age children at risk by year 2010. The Brazilian Ministry of Health (MoH) recommends biennial surveys of whole communities and treatment of the positives through the Schistosomiasis Control Program within the Unified Health System (PCE-SUS). However, by 2004 the PCE-SUS had covered only 8.4% of the 1.2 million residents in the Rainforest Zone of Pernambuco (ZMP). Six of the 43 municipalities still remained unattended. Only three of the municipalities already surveyed reached coverage of 25% or more. At least 154 thousand children in the 7-14 years old range have to be examined (and treated if positive) within the next five years to attend the minimum target of the WHA 54.19 for the ZMP. To make this target feasible, it is suggested that from 2006 to 2010 the PCE-SUS actions should be complemented with school-based diagnosis and treatment, involving health and educational organs as well as community associations to include both children in schools and non-enrolled school-age children.

Prediction of soil orders with high spatial resolution: response of different classifiers to sampling density

The objective of this work was to evaluate sampling density on the prediction accuracy of soil orders, with high spatial resolution, in a viticultural zone of Serra Gaúcha, Southern Brazil. A digital elevation model (DEM), a cartographic base, a conventional soil map, and the Idrisi software were used. Seven predictor variables were calculated and read along with soil classes in randomly distributed points, with sampling densities of 0.5, 1, 1.5, 2, and 4 points per hectare. Data were used to train a decision tree (Gini) and three artificial neural networks: adaptive resonance theory, fuzzy ARTMap; self‑organizing map, SOM; and multi‑layer perceptron, MLP. Estimated maps were compared with the conventional soil map to calculate omission and commission errors, overall accuracy, and quantity and allocation disagreement. The decision tree was less sensitive to sampling density and had the highest accuracy and consistence. The SOM was the less sensitive and most consistent network. The MLP had a critical minimum and showed high inconsistency, whereas fuzzy ARTMap was more sensitive and less accurate. Results indicate that sampling densities used in conventional soil surveys can serve as a reference to predict soil orders in Serra Gaúcha.

Minimum number of assessment times to compare chemical control treatments for papaya fruit anthracnose

The chemical treatment evaluation in the field to control post-harvest fruit anthracnose (Colletotrichum gloeosporioides) requires a suitable disease incidence assessment on harvested papaya (Carica papaya) fruits. The minimum number of papaya fruit harvests was determined for valid treatment comparison in field trials for anthracnose chemical control. Repeatability analysis was done using previously published data. The coefficient determination (R²) estimate range, using four methods, and based on means of 12 assessment times, was 92.58 < R² < 94.45%. The number of assessment times required for R²=90% varied from seven to nine. The R² values of 85.1 < R² < 91.3% estimated by ANOVA suggested that any seven successive assessment times were sufficient for treatment comparison.

Influence of different systems of minimum ventilation on air quality in broiler houses

To maintain a competitive development of the Brazilian aviculture, some measures must be taken to enable the identification and reduction of risks to the health of birds, as well as for the physical environment. Therefore, the aim of this study was to evaluate the effectiveness of three different systems of minimum ventilation (positive pressure - SVMP, negative pressure - SVMN and natural ventilation - SVMNat) in the air quality during the first 21 days of life of broiler chicks, during winter. Three points were selected along the length to verify ammonia, carbon monoxide and oxygen concentrations at 3a.m., 9a.m., 3p.m. and 9p.m., by the respiration level of birds and workers. The averages of pollutant gases did not exceed the tolerance levels for the three minimum ventilation systems evaluated, which is 20 and 10ppm for the birds level and 20 and 39ppm for the workers level, for ammonia and carbon monoxide, respectively. It was evident that the minimum ventilation systems were appropriately sized for the required minimum ambient air renovation, in respect to ventilation rates applied for the SVMN and SVMP systems, and with air velocity at levels that do not stress the chicks, including for the SVMNat. The three studied systems of minimum ventilation allowed the birds to externalize their productive performance, with values close to the ones considered satisfactory for all evaluated parameters, in accordance with the Brazilian aviculture standards.

Multivariate statistical analysis to support the minimum streamflow regionalization

ABSTRACT This study aimed to develop a methodology based on multivariate statistical analysis of principal components and cluster analysis, in order to identify the most representative variables in studies of minimum streamflow regionalization, and to optimize the identification of the hydrologically homogeneous regions for the Doce river basin. Ten variables were used, referring to the river basin climatic and morphometric characteristics. These variables were individualized for each of the 61 gauging stations. Three dependent variables that are indicative of minimum streamflow (Q7,10, Q90 and Q95). And seven independent variables that concern to climatic and morphometric characteristics of the basin (total annual rainfall – Pa; total semiannual rainfall of the dry and of the rainy season – Pss and Psc; watershed drainage area – Ad; length of the main river – Lp; total length of the rivers – Lt; and average watershed slope – SL). The results of the principal component analysis pointed out that the variable SL was the least representative for the study, and so it was discarded. The most representative independent variables were Ad and Psc. The best divisions of hydrologically homogeneous regions for the three studied flow characteristics were obtained using the Mahalanobis similarity matrix and the complete linkage clustering method. The cluster analysis enabled the identification of four hydrologically homogeneous regions in the Doce river basin.

Morphological aspects of buffaloes (Bubalus bubalis) umbilical cord

Buffalo is an important livestock resource, with a great participation in agricultural systems, providing milk, meat, and work power. Umbilical cord is responsible for maternal-fetal nutrients exchange during pregnancy, and its alterations can compromise the fetal development. We investigated ten pregnant uteruses collected from cross-bread buffaloes in different stages of gestation. Pregnancy and fetal age was determined by measuring the apex sacral length and development period was calculated by previously published formula. Umbilical cords were measured for length determination. Umbilical cord vascular net and anastomosis were observed by injection of Neoprene latex. Histological sections of the umbilical cord were studied after stain with HE, picrossirius, toluidine blue, orceine, and PAS reaction. Buffaloes' umbilical cord was formed by two central arteries, an allantois duct and two peripheral veins. The artery wall was composed by large quantity of collagen, elastic fibers, fibroblasts and large number of vasa vasorum. The allantois duct was located between the arteries and presented a great number of small nourishing vessels. Small nourishing vessels should be carefully considered to avoid to be mistaken to the arterials and veins vasa vasorum. Medium length of umbilical cord from buffalos was 11.8cm (minimum of 6.8cm and maximum of 17.4cm).

Numerical Simulation of the Cavitation in the Hydrodynamic Lubrication of Journal Bearings: a Parallel Algorithm

In this paper we present an algorithm for the numerical simulation of the cavitation in the hydrodynamic lubrication of journal bearings. Despite the fact that this physical process is usually modelled as a free boundary problem, we adopted the equivalent variational inequality formulation. We propose a two-level iterative algorithm, where the outer iteration is associated to the penalty method, used to transform the variational inequality into a variational equation, and the inner iteration is associated to the conjugate gradient method, used to solve the linear system generated by applying the finite element method to the variational equation. This inner part was implemented using the element by element strategy, which is easily parallelized. We analyse the behavior of two physical parameters and discuss some numerical results. Also, we analyse some results related to the performance of a parallel implementation of the algorithm.

Determination of anaerobic threshold in rats using the lactate minimum test

The break point of the curve of blood lactate vs exercise load has been called anaerobic threshold (AT) and is considered to be an important indicator of endurance exercise capacity in human subjects. There are few studies of AT determination in animals. We describe a protocol for AT determination by the "lactate minimum test" in rats during swimming exercise. The test is based on the premise that during an incremental exercise test, and after a bout of maximal exercise, blood lactate decreases to a minimum and then increases again. This minimum value indicates the intensity of the AT. Adult male (90 days) Wistar rats adapted to swimming for 2 weeks were used. The initial state of lactic acidosis was obtained by making the animals jump into the water and swim while carrying a load equivalent to 50% of body weight for 6 min (30-s exercise interrupted by a 30-s rest). After a 9-min rest, blood was collected and the incremental swimming test was started. The test consisted of swimming while supporting loads of 4.5, 5.0, 5.5, 6.0 and 7.0% of body weight. Each exercise load lasted 5 min and was followed by a 30-s rest during which blood samples were taken. The blood lactate minimum was determined from a zero-gradient tangent to a spline function fitting the blood lactate vs workload curve. AT was estimated to be 4.95 ± 0.10% of body weight while interpolated blood lactate was 7.17 ± 0.16 mmol/l. These results suggest the application of AT determination in animal studies concerning metabolism during exercise.

Peritoneal and serum interleukin-18 levels are not increased in women with minimum or mild endometriosis

Interleukin-18 (IL-18) is a cytokine that belongs to the IL-1 family. Endometriosis is strongly associated with sub-fertility, and affects about 15% of women of reproductive age. IL-18 may favor the progression of endometriosis. The objective of the present study was to determine the concentration of IL-18 in the serum and peritoneal fluid of infertile women with endometriosis. Forty infertile and 25 fertile women were screened in a teaching hospital. Thirty-four infertile patients with minimal or mild endometriosis and 22 fertile controls were enrolled in the study. The primary outcome was the estimate of IL-18 levels and the secondary outcome was the correlation between serum and peritoneal levels of IL-18. There were no differences between the two groups regarding age, body mass index and levels of peritoneal fluid IL-18 (mean ± SD): 290.85 ± 173.02 pg/mL for infertile women vs 374.21 ± 330.15 pg/mL for controls; or serum IL-18: 391.07 ± 119.71 pg/mL for infertile women vs 373.42 ± 129.11 pg/mL for controls. However, a positive association was found between serum and peritoneal IL-18 levels in patients with endometriosis: r = 0.794, P = 0.0001. All measurements were carried out at the same time by the Human IL-18 Immuno Assay ELISA kit (MBL Co. Ltd., Japan). The present study did not find evidence supporting the hypothesis that IL-18 levels are associated with infertility in women with minimal and mild endometriosis, although a positive correlation was detected in these women between peritoneal and serum levels of IL-18.

Comparison of bone quantity by ultrasound measurements of phalanges between white and black children living in Paraná, Brazil, with Europeans

The objective of this study was to determine bone quantity by ultrasound measurements of the proximal finger phalanges (AD-SoS = amplitude-dependent speed of sound) of healthy Brazilian schoolchildren living in Paraná, Brazil and to compare these values with European populations. The sample was composed of 1356 Brazilian schoolchildren of both genders (660 males, 696 females), aged 6 to 11 years, divided into white (840) and black (516) groups and compared to age- and gender-matched Europeans. AD-SoS of the schoolchildren increased significantly with age for both genders. Significantly higher AD-SoS values were observed for the white children (1916 ± 58) compared to their black counterparts (1898 ± 72) and for the female gender (1920 ± 61) compared to the male gender (1898 ± 66). Overall, the AD-SoS outcomes for females were similar to those of European studies. However, the AD-SoS of the Brazilian schoolchildren of both genders and skin colors was lower than that reported for children in Poland. AD-SoS outcomes for Brazilian schoolboys were similar to those obtained in Italian studies and were lower than those of the Spanish children. In conclusion, Brazilian schoolchildren of both genders and skin colors showed lower bone quantities than Polish children and Spanish males, and levels similar to Italian children and Spanish females.