Numerical study of pneumatic conveying of powders

The dense phase mode may be advantageous over the dilute phase mode, for some pneumatic conveying problems, because it causes less erosion of the pipeline, less attrition of the material, requires less dust collection and is effective even for smaller pipe diameters. The objective of this study is to numerically determine the parameters that govern the formation slugs in dense phase conveying. The distributed Lagrange multiplier/fictitious domain method (Glowinski et al. 1998 and Singh et al. 2000) is used to perform direct simulations of the motion of solid and gas phases in pipes with rectangular cross-sections. In this approach the exact governing equations are solved at scales finer than the particle size and no ad hoc two-phase flow model is used. Simulations are started by placing a particle slug in the flow. Several cases were simulated to understand the role of gravity, the particle density and the strength of applied pressure gradient in the formation and destruction of slugs. When the applied pressure gradient is increased the slugs become more compact, their velocity in the flow direction increases and they remain intact for longer time durations. A reduction in the pressure gradient, on the other hand, causes the particle velocity to decrease and consequently they sediment and simply roll on the bottom. The reduced gravity causes the slug to disintegrate and the center of mass of the slug moves upwards against gravity. The increased viscosity of the fluid, for a fixed pressure gradient, causes the particle to settle on the bottom of the channel under gravity

Teacher Evaluation as a Function of the Students' Sex and Achievement Level

This study was designed to determine how the ratingsof a college teacher were influenced by the sex and achievement levelof the students. Sixty-seven male and 73 female undergraduates wereused in the main analyses, with an additional 72 subjects insubsidiary analyses. During the first week of the course subjectswere asked to rate themselves, father, mother,and the instructor inthe course on the Michill Adjective Rating Scale (MAILS) whichmeasures four relatively independent factors (unhappiness,extraversion, self-assertiveness, and productive persistence). Theyalso rated themselves and the instructor on the same scale near theend of the course, rated the instructor on the Rating Scale forTeachers pm consisting of 17 itmes dealing with aspects of ateacher's job and personality, and took five teacher-made achievementtests during the semester. Students were separated into high and lowachievement levels, using the median of the cutoff. Two-waymultivariate analysis showed significant differences in teacherratings on MARS and RST factors between the sexes and between highand low achievement level subjects. Also, significant sex and achievement level interaction was found for the RST data

İki tarla bitkisinde Euphorbia hirta ve PEG 6000 ile oluşan engelleyici etkilerin karşılaştırması üzerine bir ön çalışma

Euphorbia hirta is commonly found in all tropical regions of the world, as invasive weed with an adverse effect on other plants. The current study features two important aspects: (i), Effects of E. hirta roots exudates (0, 50, 75 and 100% concentrations) (ii), Influence of PEG 6000 “Polyethylene glycol” (8, 16 and 40 g/l concentrations) on germination and growth criterion of Cicer arietinum (Chick pea) and Phaseolus vulgaris (French bean). In this regard osmotic potential of all the solutions have been balanced. It is observed that the root leachates of spurge weed significantly (p < 0.05) affected the germination rate while PEG has no positive or negative effect on growth activity. The growth parameters in both crops have altered by spurge weed and PEG solutions while highest inhibition was recorded in root length root exudates (3.5 cm) of C. arietinum which is in contrast to PEG (11.97 cm), this might be due to the presence of allelochemicals. The prescribed treatments also raised their pH values, where highest pH (7.9) obtained from 100% spurge weed induction which is relatively a stronger basic nature rather than neutral control samples. Comparative studies of both test crops shows that C. arietinum has appeared to be more influential than P. vulgaris. Two-way ANOVA has produced a significant difference (p < 0.05) between the effects of both treatments on germination and growth of test crops while within group (concentrations of each treatment) are weakly significant (p < 0.1) to each other. This would rather intimates that the inhibition has strongly emerged as an allelopathic response on Cicer arietinum and Phaseolus vulgaris plants by the induction of spurge weed (Euphorbia hirta) root exudates.Euphorbia hirta, diğer bitkiler üzerinde olumsuz etkiye sahip istilacı bir yabancı ot türü olarak dünyanın bütün tropikal bölgelerinde yaygın olarak bulunmaktadır. Yürütülen çalışmada, Phaseolus vulgaris L. (Fasulye) ve Cicer arietinum L. (Nohut) çimlenme ve büyüme kriteri üzerine (i) E. hirta'nın kök salgılarının etkileri (0, 50, 75 ve %100 konsantrasyon), (ii) PEG 6000'nin (8, 16 ve 40 g/l konsantrasyon) “Polietilen glikol” etkisi olmak üzere iki önemli husus bulunmaktadır. Bu bakımdan bütün solüsyonların osmotik potansiyeli dengelenmiştir. Sütleğen bitkisinin kök salgılarının çimlenme oranını önemli ölçüde (p <0.05) etkilediği, PEG'in ise büyüme aktivitesi üzerinde olumlu veya olumsuz bir etkisinin olmadığı gözlemlenmiştir. PEG solüsyonları ve sütleğen bitkisi her iki üründeki büyüme parametrelerini değiştirmiş, C. arietinum'un kök uzunluğunda PEG (11.97 cm)'in aksine en yüksek oranda inhibisyon kök salgıları uygulamasında (3.5 cm) kaydedilmiştir. Bu durum alelokimyasalların varlığından kaynaklanmış olabilir. En yüksek pH (7.9) nötr kontrol örneklerine göre daha güçlü bir bazik yapısı olan %100 sütleğen otu indüksiyonundan elde edilmiş, yapılan uygulamalar ayrıca pH değerlerini de yükseltmiştir. Çalışmadaki her iki test bitkisi karşılaştırıldığında C. arietinum'un P. vulgaris'ten daha fazla etkilendiği görülmüştür. İki yönlü varyans analizine göre (Two-way ANOVA) her iki uygulamanın test bitkilerinin çimlenme ve büyümesi üzerindeki etkileri grup içerisinde (her bir uygulama konsantrasyonları) az oranda önemli olmasına rağmen (p <0.1) her iki uygulama arasında önemli bir fark (p <0.05) oluşturmuştur. Bu inhibisyonun sütleğen bitkisinin (Euphorbia hirta) kök salgılarının Cicer arietinum ve Phaseolus vulgaris bitkileri üzerine alelopatik etkisine karşı güçlü bir yanıt olarak ortaya çıktığı düşünülmektedir

1,4-Bis(pyrimidin-2-yl­sulfanyl)­butane

The –SCH2CH2CH2CH2S– portion of the title compound, C12H14N2S2, adopts an extended zigzag conformation. The angles at the tetra­hedral carbon atoms are marginally increased [113.63 (12)° and 111.38 (17)° for S—C—C and C—C—C respectively] from the idealized tetra­hedral angle. The mol­ecule lies on an inversion center located at the mid-point of the butyl chain. In the crystal, there is a π–π stacking inter­action between inversion-related pyrimidine rings with mean inter­planar spacing of 3.494 (2) Å

Extraction and Partial Characterization of Collagen from Different Animal Skins

Collagen is a wonder triple helix fibrous protein. Basically, it connects and supports other bodily tissues, such as skin, bone, tendons, muscles and cartilage. In fact, it makes up about 25% of the total amount of proteins. Collagen possesses great tensile strength. In the present investigation, three methods of collagen extraction were employed. Out of which the method of George and Chandrakasan (1996) proved to be a better method for collagen extraction in chicken and human skins. Regarding Goat and Buffalo skins, collagen was extracted using TCA method wherein the extracted fibrous protein got hydrolyzed, getting denatured therefore, a definite band pattern was not obtained. By comparing the electrophoretic profile of various animal skins, a definite band pattern can be obtained which will indicate differences in collagen structure thereby facilitating species and generic differentiation

Kandidatų ir vertintojų lyties įtaka sprendimo priėmimui tariamoje įdarbinimo situacijoje

Gender stereotypes have determined that the concepts of management and leadership are more associated with men than women. There are more men working in management positions than women in various countries, including Lithuania. The most widely discussed cause for that is discrimination against women in the labor market. The aim of the study was to examine evaluation differences between personnel specialists and comparison group, depending on their own and candidate‘s gender. Study was based on quasi-experimental strategy which included a hiring simulation. Participants had to evaluate potential candidates, a man and a woman, seeking for a job in management position. Data was collected from 128 people (age range - 19 to 56 years): 48 personnel specialists (M=29,38; SD=7,48), 49 women, who represented other specialties (M=26,29; SD=7,36) and 31 men, who represented other specialties (M=25,39; SD=5,05). Both personnel specialists and comparison group evaluated man and woman-candidate as similar. There were no significant differences between the two candidates on their hireability, reliability, competence, potential salary and promotability. However, results also indicate that personnel specialists and women, representing other specialties, suggested that man was more capable to work in teams than woman. The study gives an insight about the possibility of gender stereotype change.Lyčių stereotipai paprastai apsprendžia, kad vadovavimas ir lyderystė yra labiau siejami su vyrais nei moterimis. Įvairiose pasaulio šalyse, tarp jų ir Lietuvoje, mažesnė dalis moterų dirba vadovaujamose pozicijose lyginant su vyrais. Tokį skirtumą galėtų lemti daugybė priežasčių, tačiau dažniausiai aptariama - moterų diskriminacija darbo rinkoje. Pirmasis žingsnis, kurį atliekame besidarbindami, yra personalo atranka, todėl būtų galima daryti prielaidą, kad moterų diskriminacija atsiranda jau šiame etape. Šio tyrimo metu buvo naudota kvazieksperimentinė tyrimo strategija. Įdarbinimo simuliacijos metu tyrimo dalyviai (personalo specialistai ir palyginamoji grupė) turėjo vertinti potencialius kandidatus vyrą ir moterį, siekiančius įsidarbinti vadovaujamai pozicijai. Tyrimo tikslas buvo nustatyti, kaip skiriasi personalo specialistų ir palyginamosios grupės vertinimai, priklausomai nuo pačių vertintojų ir kandidato lyties, įdarbinant kandidatus vadovaujamai pozicijai. Pagrindiniame tyrime dalyvavo 128 asmenys. Nustatyta, jog tiek personalo specialistės, tiek palyginamoji grupė potencialaus kandidato vyro ir moters įdarbinimo tikimybę, patikimumą, kompetenciją, skiriamą algą bei paaukštinimo tikimybę vertino panašiai.&nbsp; Rasti skirtumai tarp suvokto kandidatų gebėjimo dirbti komandoje - personalo specialistės ir kitų specialybių atstovės moterys manė, kad vyrui geriau pavyks dirbti komandoje. Tyrimo rezultatai leidžia daryti išvadą, kad lytis neturi &nbsp;reikšmingos įtakos darbinantis vidutinio lygio vadovo pareigoms

Large Retroperitoneal Paraganglioma Associated with Germline Mutation of the Succinate Dehydrogenase Gene

Paragangliomas (PGLs) are rare neural tumors that can be benign or malignant and often associated with familial syndromes. We present a case of a 23-year-old male with a large retroperitoneal PGL found incidentally during the workup of elevated liver enzymes. After surgical excision, the patient was found to have an autosomal dominant mutation in the succinate dehydrogenase B (SDHB) gene, which when compared to sporadic PGLs or other familial syndromes is associated with a higher risk of tumor recurrence, occult metastasis, and development of other cancers. The patient’s first-degree relatives were recommended to undergo screening for the genetic mutation

Percutaneous needle biopsy for indeterminate renal masses: a national survey of UK consultant urologists

<p>Abstract</p> <p>Background</p> <p>The use of percutaneous needle biopsy in the evaluation of indeterminate renal masses is controversial and its role in management remains largely unclear. We set to establish current practice on this issue in UK urology departments.</p> <p>Methods</p> <p>We conducted a national questionnaire survey of all consultant urologists in the UK, to establish current practice and attitudes towards percutaneous needle biopsy in the management of indeterminate renal masses.</p> <p>Results</p> <p>139 (43%) consultant urologists never use biopsy, whereas 111 (34%) always employ it for the diagnosis of indeterminate renal masses. 75 (23%) urologists use biopsy only for a selected patient group. Mass in a solitary kidney, bilateral renal masses and a past history of non-renal cancer were the main indications for use of percutaneous biopsy. The risk of false negative results and biopsy not changing the eventual management of their patients were the commonest reasons not to perform biopsy.</p> <p>Conclusion</p> <p>There is a wide and varied practice amongst UK Consultant Urologists in the use of percutaneous biopsy as part of the management of indeterminate renal masses. The majority of urologists believe biopsy confers no benefit. However there is a need to clarify this issue in the wake of recent published evidence as biopsy results may provide critical information for patients with renal masses in a significant majority. It not only differentiates benign from malignant tissue but can also help in deciding the management option for patients undergoing minimally invasive treatments.</p