The molecular structure of the phosphate mineral beraunite Fe2+Fe⅗+(PO4)4(OH)5⋅4H2O– A vibrational spectroscopic study

The mineral beraunite from Boca Rica pegmatite in Minas Gerais with theoretical formula Fe2+Fe5 3+(PO4)4(OH)5⋅4H2O has been studied using a combination of electron microscopy with EDX and vibrational spectroscopic techniques. Raman spectroscopy identifies an intense band at 990 cm-1 and 1011 cm-1. These bands are attributed to the PO4 3- v, symmetric stretching mode. The m3 antisymmetric stretching modes are observed by a large number of Raman bands. The Raman bands at 1034, 1051, 1058, 1069 and 1084 together with the Raman bands at 1098, 1116, 1133, 1155 and 1174 cm-1 are assigned to the m3 antisymmetric stretching vibrations of PO4 3- and the HOPO3 2- units. The observation of these multiple Raman bands in the symmetric and antisymmetric stretching region gives credence to the concept that both phosphate and hydrogen phosphate units exist in the structure of beraunite. The series of Raman bands at 567, 582,601, 644, 661, 673, and 687 cm-1 are assigned to the PO4 3- v2 bending modes. The series of Raman bands at 437, 468, 478, 491, 503 cm-1 are attributed to the PO4 3- and OPO3 2- v4 bending modes. No Raman bands of beraunite which could be attributed to the hydroxyl stretching unit were observed. Infrared bands at 3511 and 3359 cm-1 are ascribed to the OH stretching vibration of the OH units. Very broad bands at 3022 and 3299 cm-1 are attributed to the OH stretching vibrations of water. Vibrational spectroscopy offers insights into the molecular structure of the phosphate mineral beraunite.

Mechanical tension as a driver of connective tissue growth in vitro

We propose the progressive mechanical expansion of cell-derived tissue analogues as a novel, growth-based approach to in vitro tissue engineering. The prevailing approach to producing tissue in vitro is to culture cells in an exogenous “scaffold” that provides a basic structure and mechanical support. This necessarily pre-defines the final size of the implantable material, and specific signals must be provided to stimulate appropriate cell growth, differentiation and matrix formation. In contrast, surgical skin expansion, driven by increments of stretch, produces increasing quantities of tissue without trauma or inflammation. This suggests that connective tissue cells have the innate ability to produce growth in response to elevated tension. We posit that this capacity is maintained in vitro, and that order-of-magnitude growth may be similarly attained in self-assembling cultures of cells and their own extracellular matrix. The hypothesis that growth of connective tissue analogues can be induced by mechanical expansion in vitro may be divided into three components: (1) tension stimulates cell proliferation and extracellular matrix synthesis; (2) the corresponding volume increase will relax the tension imparted by a fixed displacement; (3) the repeated application of static stretch will produce sustained growth and a tissue structure adapted to the tensile loading. Connective tissues exist in a state of residual tension, which is actively maintained by resident cells such as fibroblasts. Studies in vitro and in vivo have demonstrated that cellular survival, reproduction, and matrix synthesis and degradation are regulated by the mechanical environment. Order-of-magnitude increases in both bone and skin volume have been achieved clinically through staged expansion protocols, demonstrating that tension-driven growth can be sustained over prolonged periods. Furthermore, cell-derived tissue analogues have demonstrated mechanically advantageous structural adaptation in response to applied loading. Together, these data suggest that a program of incremental stretch constitutes an appealing way to replicate tissue growth in cell culture, by harnessing the constituent cells’ innate mechanical responsiveness. In addition to offering a platform to study the growth and structural adaptation of connective tissues, tension-driven growth presents a novel approach to in vitro tissue engineering. Because the supporting structure is secreted and organised by the cells themselves, growth is not restricted by a “scaffold” of fixed size. This also minimises potential adverse reactions to exogenous materials upon implantation. Most importantly, we posit that the growth induced by progressive stretch will allow substantial volumes of connective tissue to be produced from relatively small initial cell numbers.

Infrared and Raman spectroscopic characterization of the Borate mineral Vonsenite

There are a large number of boron-containing minerals, of which vonsenite is one. Some discussion about the molecular structure of vonsenite exists in the literature. Whether water is involved in the structure is ill-determined. The molecular structure of vonsenite has been assessed by the combination of Raman and infrared spectroscopy. The Raman spectrum is characterized by two intense broad bands at 997 and 1059 cm−1 assigned to the BO stretching vibrational mode. A series of Raman bands in the 1200–1500 cm−1 spectral range are attributed to BO antisymmetric stretching modes and in-plane bending modes. The infrared spectrum shows complexity in this spectral range. No Raman spectrum of water in the OH stretching region could be obtained. The infrared spectrum shows a series of overlapping bands with bands identified at 3037, 3245, 3443, 3556, and 3614 cm−1. It is important to understand the structure of vonsenite in order to form nanomaterials based on its structure. Vibrational spectroscopy enables a better understanding of the structure of vonsenite.

Vibrational spectroscopy of the copper (II) disodium sulphate dihydrate mineral kröhnkite Na2Cu(SO4)2 · 2H2O

A natural single-crystal specimen of the kröhnkite from Chuquicamata, Chile, with the general formula Na2Cu(SO4)2 · 2H2O, was investigated by Raman and infrared spectroscopy. The mineral kröhnkite is found in many parts of the world's arid areas. Kröhnkite crystallizes in the monoclinic crystal system with point group 2/m and space group P21/c. It is an uncommon secondary mineral formed in the oxidized zone of copper deposits, typically in very arid climates. The Raman spectrum of kröhnkite dominated by a very sharp intense band at 992 cm−1 is assigned to the ν1 symmetric stretching mode and Raman bands at 1046, 1049, 1138, 1164, and 1177 cm−1 are assigned to the ν3 antisymmetric stretching vibrations. The infrared spectrum shows an intense band at 992 cm−1. The Raman bands at 569, 582, 612, 634, 642, 655, and 660 cm−1 are assigned to the ν4 bending modes. Three Raman bands observed at 429, 445, and 463 cm−1 are attributed to the ν2 bending modes. The observation that three or four bands are seen in the ν4 region of kröhnkite is attributed to the reduction of symmetry to C2v or less.

On cloud computing service considerations for the small and medium enterprises

The concept of cloud computing services is appealing to the small and medium enterprises (SMEs), with the opportunity to acquire modern information technology resources as a utility and avoid costly capital investments in technology resources. However, the adoption of the cloud computing services presents significant challenges to the SMEs. The SMEs need to determine a path to adopting the cloud computing services that would ensure their sustainable presence in the cloud computing environment. Information about approaches to adopting the cloud computing services by the SMEs is fragmented. Through an interpretive design, we suggest that the SMEs need to have a strategic and incremental intent, understand their organizational structure, understand the external factors, consider the human resource capacity, and understand the value expectations from the cloud computing services to forge a successful path to adopting the cloud computing services. These factors would contribute to a model of cloud services for SMEs.

Evolving a design driven ‘hybrid’ research approach to inform and advance sustainable outcomes in the built environment sector

A significant reduction in global greenhouse gas (GHG) emissions is a priority, and the preservation of existing building stock presents a significant opportunity to reduce the carbon footprint of our built environment. Within this ‘wicked’ problem context, and moving beyond the ad hoc and incremental performance improvements that have been made to date, collaborative and multidisciplinary efforts are required to find rapid and transformational solutions. Design has emerged as a strategic and redirective practice, and lessons can therefore be learned about transformation and potentially applied in the built environment. The purpose of this paper is to discuss a pragmatic and novel research approach for undertaking such applied design driven research. This paper begins with a discussion of key contributions from design science (rational) and action research (reflective) philosophies in creating an emerging methodological ‘hybrid design approach’. This research approach is then discussed in relation to its application to specific research exploring the processes, methods and lessons from design in heritage building retrofit projects. Drawing on both industry and academic knowledge to ensure relevance and rigour, it is anticipated that the hybrid design approach will be useful for others tackling such complex wicked problems that require context-specific solutions.

Web crippling tests of hollow flange channel beams – end one flange and interior one flange load cases

LiteSteel beam (LSB) is a new cold-formed steel hollow flange channel section produced using a patented manufacturing process involving simultaneous cold-forming and dual electric resistance welding. The LSBs were commonly used as floor joists and bearers with web openings in residential, industrial and commercial buildings. Due to the unique geometry of LSBs, as well as its unique residual stress characteristics and initial geometric imperfections resultant of manufacturing processes, much of the existing research for common cold-formed steel sections is not directly applicable to LSBs. Many research studies have been carried out to evaluate the behaviour and design of LSBs subject to pure bending actions, predominant shear and combined actions. However, to date, no investigation has been conducted into the web crippling behaviour and strength of LSB sections. Hence detailed experimental studies were conducted to investigate the web crippling behaviour and strengths of LSBs under EOF (End One Flange) and IOF (Interior One Flange) load cases. A total of 26 web crippling tests was conducted and the results were compared with current AS/NZS 4600 design rules. This comparison showed that AS/NZS 4600 (SA, 2005) design rules are very conservative for LSB sections under EOF and IOF load cases. Suitable design equations have been proposed to determine the web crippling capacity of LSBs based on experimental results. This paper presents the details of this experimental study on the web crippling behaviour and strengths of LiteSteel beams under EOF and IOF load cases.

Numerical modelling and design of lipped channel beams subject to shear

Cold-formed steel members are increasingly used as primary structural elements in buildings due to the availability of thin and high strength steels and advanced cold-forming technologies. Cold-formed lipped channel beams (LCB) are commonly used as flexural members such as floor joists and bearers. Many research studies have been carried out to evaluate the behaviour and design of LCBs subject to pure bending actions. However, limited research has been undertaken on the shear behaviour and strength of LCBs. Hence a numerical study was undertaken to investigate the shear behaviour and strength of LCBs. Finite element models of simply supported LCBs with aspect ratios of 1.0 and 1.5 were considered under a mid-span load. They were then validated by comparing their results with test results and used in a detailed parametric study based on the validated finite element models. Numerical studies were conducted to investigate the shear buckling and post-buckling behaviour of LCBs. Experimental and numerical results showed that the current design rules in cold-formed steel structures design codes are very conservative for the shear design of LCBs. Improved design equations were therefore proposed for the shear strength of LCBs. This paper presents the details of this numerical study of LCBs and the results.

Effect of real support conditions on the shear strength of hollow flange channel beams

This paper presents the details of experimental studies on the effect of real support conditions on the shear strength of LiteSteel beams (LSB). The LSB has a unique shape of a channel beam with two rectangular hollow flanges, made using a unique manufacturing process. In some applications in the building industry LSBs are used with only one web side plate (WSP) at their supports and are not used with full height web side plates (WSP) at their supports. Past research studies showed that theses real support connections did not provide simply supported conditions. Many studies have been carried out to evaluate the behaviour and design of LSBs with simply supported conditions subject to pure bending and predominant shear actions. To date, however, no investigation has been conducted into the effect of real support conditions on the shear strength of LSBs. Hence detailed experimental studies were undertaken to investigate the shear behaviour and strength of LSBs with real support conditions. A total of 28 experimental tests were conducted as part of the studies. Simply supported test specimens of LSBs with aspect ratios of 1.0 and 1.5 were loaded at mid-span until failure. It was found that the effect of using one WSP on the shear behaviour of LSB is significant and there is about 25% shear capacity reduction due to the lateral movement of the bottom flange at the supports. Shear capacity of LSB was also found to decrease when full height WSPs were not used. Suitable support connections were developed to improve the shear capacity of LSBs based on test results.

Web crippling tests of hollow flange channel beams : ETF AND ITF load cases

This paper presents the details of an experimental study of a cold-formed steel hollow flange channel beam known as LiteSteel Beam (LSB) subject to web crippling actions (ETF and ITF). Due to the geometry of the LSB, as well as its unique residual stress characteristics and initial geometric imperfections resultant of manufacturing processes, much of the existing research for common cold-formed steel sections is not directly applicable to LSB. Experimental and numerical studies have been carried out to evaluate the behaviour and design of LSBs subject to pure bending actions, predominant shear actions and combined actions. To date, however, no investigation has been conducted into the web crippling behaviour and strength of LSB sections under ETF and ITF load conditions. Hence experimental studies were conducted to assess the web crippling behaviour and strengths of LSBs. Twenty eight web crippling tests were conducted and the results were compared with the current AS/NZS 4600[1] and AISI S100 [2]design equations. Comparison of the ultimate web crippling capacities from tests showed that AS/NZS 4600[1] and AISI S100 [2] design equations are unconservative for LSB sections under ETF and ITF load cases. Hence new equations were proposed to determine the web crippling capacities of LSBs. Suitable design rules were also developed under the DSM format.

Molecular structural studies of the amorphous mineral pitticite Fe, AsO4, SO4, H2O

Some minerals are colloidal and show no X-ray diffraction patterns. Vibrational spectroscopy offers one of the few methods for the assessment of the structure of these types of mineral. Among this group of minerals is pitticite simply described as Fe, AsO4, SO4, H2O. The objective of this research is to determine the molecular structure of the mineral pitticite using vibrational spectroscopy. Raman microscopy offers a useful method for the analysis of such colloidal minerals. Raman and infrared bands are attributed to the , and water stretching vibrations. The Raman spectrum is dominated by a very intense sharp band at 983 cm−1 assigned to the symmetric stretching mode. A strong Raman band at 1041 cm−1 is observed and is assigned to the antisymmetric stretching mode. Low intensity Raman bands at 757 and 808 cm−1 may be assigned to the antisymmetric and symmetric stretching modes. Raman bands observed at 432 and 465 cm−1 are attributable to the doubly degenerate ν2(SO4)2- bending mode.

Lumbar epidural steroids are not cost effective in sciatica

Background Lumbar Epidural Steroids Injections (ESI’s) have previously been shown to provide some degree of pain relief in sciatica. Number Needed To Treat (NNT) to achieve 50% pain relief has been estimated at 7 from the results of randomised controlled trials. Pain relief is temporary. They remain one of the most commonly provided procedures in the UK. It is unknown whether this pain relief represents good value for money. Methods 228 patients were randomised into a multi-centre Double Blind Randomised Controlled Trial. Subjects received up to 3 ESI’s or intra-spinous saline depending on response and fall off with the first injection. All other treatments were permitted. All received a review of analgesia, education and physical therapy. Quality of life was assessed using the SF36 at 6 points and compared using independent sample t-tests. Follow up was up to 1 yr. Missing data was imputed using last observation carried forward (LOCF). QALY’s (Quality of Life Years) were derived from preference based heath values (summary health utility score). SF-6D health state classification was derived from SF-36 raw score data. Standard gambles (SG) were calculated using Model 10. SG scores were calculated on trial results. LOCF was not used for this. Instead average SG were derived for a subset of patients with observations for all visits up to week 12. Incremental QALY’s were derived as the difference in the area between the SG curve for the active group and placebo group. Results SF36 domains showed a significant improvement in pain at week 3 but this was not sustained (mean 54 Active vs 61 Placebo P<0.05). Other domains did not show any significant gains compared with placebo. For derivation of SG the number in the sample in each period differed. In week 12, average SG scores for active and placebo converged. In other words, the health gain for the active group as measured by SG was achieved by the placebo group by week 12. The incremental QALY gained for a patient under the trial protocol compared with the standard care package was 0.0059350. This is equivalent to an additional 2.2 days of full health. The cost per QALY gained to the provider from a patient management strategy administering one epidural as suggested by results was £25 745.68. This result was derived assuming that the gain in QALY data calculated for patients under the trial protocol would approximate that under a patient management strategy based on the trial results (one ESI). This is above the threshold suggested by some as a cost effective treatment. Conclusions The transient benefit in pain relief afforded by ESI’s does not appear to be cost-effective. Further work is needed to develop more cost-effective conservative treatments for sciatica.

Task modeling for collaborative authoring

Motivation ?Task analysis for designing modern collaborative work needs a more fine grained approach. Especially in a complex task domain, like collaborative scientific authoring, when there is a single overall goal that can only be accomplished only by collaboration between multiple roles, each requiring its own expertise. We analyzed and re-considered roles, activities, and objects for design for complex collaboration contexts. Our main focus is on a generic approach to design for multiple roles and subtasks in a domain with a shared overall goal, which requires a detailed approach. Collaborative authoring is our current example. This research is incremental: an existing task analysis approach (GTA) is reconsidered by applying it to a case of complex collaboration. Our analysis shows that designing for collaboration indeed requires a refined approach to task modeling: GTA, in future, will need to consider tasks at the lowest level that can be delegated or mandates. These tasks need to be analyzed and redesigned in more in detail, along with the relevant task object.

Photoelectron spectroscopy of HCCN- and HCNC- reveals the quasilinear triplet carbenes, HCCN and HCNC

Negative ion photoelectron spectroscopy has been used to study the HCCN- and HCNC- ions. The electron affinities (EA) of cyanocarbene have been measured to be EA(HCCN (X) over tilde (3)Sigma(-)=2.003+/-0.014 eV and EA(DCCN (X) over tilde (3)Sigma(-))=2.009+/-0.020 eV. Photodetachment of HCCN- to HCCN (X) over tilde (3)Sigma(-) shows a 0.4 eV long vibrational progression in nu(5), the H-CCN bending mode; the HCCN- photoelectron spectra reveal excitations up to 10 quanta in nu(5). The term energies for the excited singlet state are found to be T-0(HCCN (a) over tilde (1)A('))=0.515+/-0.016 eV and T-0(DCCN (a) over tilde (1)A('))=0.518+/-0.027 eV. For the isocyanocarbene, the two lowest states switch and HCNC has a singlet ground state and an excited triplet state. The electron affinities are EA(HCNC (X) over tilde (1)A('))=1.883+/-0.013 eV and EA((X) over tilde (1)A(') DCNC)=1.877+/-0.010 eV. The term energy for the excited triplet state is T-0(HCNC (a) over tilde (3)A("))=0.050+/-0.028 eV and T-0(DCNC (a) over tilde (3)A("))=0.063+/-0.030 eV. Proton transfer kinetics in a flowing afterglow apparatus were used to re-measure the enthalpy of deprotonation of CH3NC to be Delta(acid)H(298)(CH3NC)=383.6+/-0.6 kcal mol(-1). The acidity/EA thermodynamic cycle was used to deduce D-0(H-CHCN)=104+/-2 kcal mol(-1) [Delta(f)H(0)(HCCN)=110+/-4 kcal mol(-1)] and D-0(H-CHNC)=106+/-4 kcal mol(-1) [Delta(f)H(0)(HCNC)=133+/-5 kcal mol(-1)]. (C) 2002 American Institute of Physics.

The ranking based constrained document clustering method and its application to social event detection

With the growing size and variety of social media files on the web, it’s becoming critical to efficiently organize them into clusters for further processing. This paper presents a novel scalable constrained document clustering method that harnesses the power of search engines capable of dealing with large text data. Instead of calculating distance between the documents and all of the clusters’ centroids, a neighborhood of best cluster candidates is chosen using a document ranking scheme. To make the method faster and less memory dependable, the in-memory and in-database processing are combined in a semi-incremental manner. This method has been extensively tested in the social event detection application. Empirical analysis shows that the proposed method is efficient both in computation and memory usage while producing notable accuracy.