Measurement of Wave Attenuation in Buried Plastic Water Distribution Pipes

Leaks in pipes are a common issue encountered in the water industry. Acoustic methods are generally successful in finding and locating leaks in metallic pipes, however, they are less effective when applied to plastic pipes. This is because leak-noise signals are heavily attenuated due to high damping in the pipe-wall and sound radiation into the soil. As result, high frequency leak noise does not travel long distances. To determine how far leak noise may travel in a pipe at any frequency, the attenuation of the wave responsible for leak noise propagation should be known. In this paper a new method to estimate this is described. The method is then applied to some measurements made on a bespoke pipe-test rig in the UK, and the results are compared with theoretical predictions.

B-mode Ultrasound and Doppler Mode for Early-stage Pregnancy Diagnosis in Shi-Tzu Bitches

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Using of a snap-through truss absorber in the attenuation of the sommerfeld effect

This work, considers a vibrating system, which consists of a snap-through truss absorber (STTA) coupled to an oscillator, under excitation of an DC motor, with an eccentricity and limited power, characterizing a non-ideal oscillator (NIO). It is aimed to use the absorber STTA, to establish the conditions, that we have the maxim attenuation of the jumpphenomenon (Sommerfeld Effect). Here, weare interestedin determining the conditions of the vibrating system, in which there arereduced amplitudes of the oscillator, when it passes through the region of resonance.

DYNAMICAL JUMP ATTENUATION IN A NON-IDEAL SYSTEM THROUGH A MAGNETORHEOLOGICAL DAMPER

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ocular ultrasonography and ultrasound biomicroscopy: applicability in clinical and ophthalmic surgery

With the advent of high frequency transducers, the use of ocular ultrasound has become widely used because it provides definitions of major ocular structures. This diagnostic tool is useful in the evaluation of ophthalmic injuries, and also used for qualitative and quantitative evaluation of intraocular and orbital lesions. It is a noninvasive, safe and fast, easy to use and can be performed in an awake animal. The ocular ultrasonography is indicated in cases of ocular opacity, when the ophthalmic examination cannot be done, and in eyes with ocular trauma or suspected orbital disease. Ultrasound biomicroscopy (UBM) is a diagnostic tool with high cost and sedation or general anesthesia is necessary, but has the advantage of evaluating structures poorly defined or visualized in the anterior segment of the eye. Therefore, this paper aims to show the importance of ocular ultrasonography and UBM to veterinary practitioners, and to demonstrate its advantages and indications in ophthalmic routine.

Ultrasound analysis of a canine patient with renal disease and chronic liver disease undergoing treatment with intravenous stem cells

With the improvement in quality of life of animals, it is increasingly frequent clinical care of elderly patients, which present renal disorders, including chronic renal failure. Recent studies report the use of stem cells to treat renal failure, which would improve the levels of urea and creatinine, and in renal ultrasound evaluation. With the present work, the idea is to report a case of ultrasonographic evaluation in a patient with chronic renal failure, liver disease and splenic nodule, which underwent stem cell therapy, where there was an improvement in the sonographic evaluation of part of the liver.

Doppler ultrasound in pregnancy assessment in bitches - literature review

Doppler ultrasound enables the assessment of blood flow in real time and has been widely used to aid in pregnancy diagnosis and monitoring in dogs and cats. This technique has a diferencial when compared with the B-mode ultrasound, as it allows the evaluation of vascular hemodynamic characteristics, while the two-dimensional ultrasound allows the diagnosis of pregnancy and fetal viability. Thus, the objective of this review is to describe how circulation is characterized in the uterine and fetal arteries in bitches during pregnancy using Doppler ultrasonography.

Abdominal ultrasound alterations in dogs with lymphoma

The aim of this study was to evaluate abdominal ultrasound images of dogs diagnosed with lymphoma. Seventy cases of dogs with lymphoma were analyzed. The animals selected were diagnosed with lymphoma which was confirmed by citology or histopathology. The most common sonographic alterations were abdominal lymphadenopathy (57.1%), hepatomegaly (54.2%) and splenomegaly (51.4%). Of the animals that had a cytology done of superficial lymph nodes, 82,8% showed diffuse sonographic changes in the liver, 54.5% had normal sonographic appearance in the spleen and enlargement of the medial iliac lymph nodes. Considering the results, we conclude that canine lymphoma is a complex disease and that it requires several laboratory tests for a correct diagnosis and prognosis.

Cerebellar tomographic attenuation of healthy felines

The cerebellum is responsible for coordination and maintenance of the fine control of muscle contraction. In cases of a suspected cerebellar disorder, a computed tomography scan can be performed to identify structural change. The aim of this study is to describe the cerebellar tomographic attenuation values in healthy cats since this variable is considered of great importance in the evaluation of images obtained by this imaging modality. A simple and a contrast enhanced brain computed tomographic scan were performed in 15 adult cats with no history of neurological symptoms and negative for feline leukemia and immunodeficiency virus. After acquiring the image, the measurement of the average attenuation of a cerebellar area of 2 centimeters in diameter was obtained. The cerebellar tomographic attenuation showed a variation from 14.60 to 25.50 HU in the simple scan and from 25.50 to 33.40 HU in the enhanced phase. Most animals (73.33%) had precontrast cerebellar attenuation values within the stipulated limit for the brain in a previous study (20-41 HU). Four animals in this study (26.67%) had values lower than 20 HU, which can be explained by differences in cellular composition between these two regions. The average value of contrast enhancement was 4.91 HU, and in none of the animals an enhancement greater than 10 HU was observed, which is in agreement with previous studies.

Ultrasound examination in gastric diseases in dogs: description of cases

Ultrasound is considered the method of choice for evaluation of the gastrintestinal wall. Thickening of the wall is the most common ultrasonographic finding in gastric disorders. Inflammatory and neoplastic disorders are the most frequent causes of wall thickening. Case report 1: Boxer, with abdominal distension, ultrasound examination detected marked diffuse thickening of the gastric wall with loss of definition of wall layers. Fine needle aspiration guided by ultrasound diagnosed gastric carcinoma. Case report 2: mixed breed dog presenting oliguria, emesis and melena, the ultrasound examination showed diffuse thickening of the gastric wall, but with preserved layers and presence of calcification areas. An inflammatory process of the gastric wall was diagnosed using cytology. The distinction between inflammatory and neoplastic processes is performed based on several factors such as distribution, symmetry, size and architecture of the parietal layer in the lesions, and ultrasonography is a valuable tool to direct diagnosis and treatment.

Application of ultrasound in the evaluation of renal abscess in a dog

Renal abscesses are rare in dogs and, although its pathogenesis is uncertain, may occur in diabetic patients with pyelonephritis, nephrolithiasis, kidney injuries or after abdominal surgery or kidney biopsy. Because of nonspecific clinical signs, laboratory tests associated with ultrasonography are important to confirm the diagnosis and treatment. Generally, kidney abscesses have sonographic aspects with different degrees of echogenicity such as hypo or hyperechoic, homogeneous or heterogeneous, and may or may not have thickened and hyperechoic walls, depending on its chronicity. Our objective was to report the use of ultrasound as a complementary method in the evaluation of disorders of the urinary tract, focusing on a case of renal abscess in a dog.

Histopathological and b-mode ultrasound characteristics in a primary canine duodenal adenocarcinoma - case report

Lower gastrointestinal tract neoplasms are rare in domestic animals, representing 3% of all biopsies and necropsies. Our objective is to describe the histopathological and B-mode ultrasound findings in a case of duodenal adenocarcinoma in a dog, since it commonly occurs in the large intestine. On ultrasound examination, there was transmural wall thickening in the duodenum with loss of layer structure, focal peritonitis and adenopathy. Histopathological examination of the intestinal mass revealed a malignant epithelial neoplasm, densely cellular and infiltrative, extending through the lamina propria, submucosa, muscle and hypodermis, characterizing a duodenal adenocarcinoma. We conclude that adenocarcinomas may be included in the differential diagnosis of transmural lesions in the duodenum in B-mode ultrasound examinations, but a laparotomy and biopsy are required for definitive diagnosis.

Effect of protective solutions and hydroxyethyl starch in the attenuation of the injuries of ischemia and reperfusion of splanchnic organs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)