5,491 research outputs found
Two-parameter differential calculus on the h-superplane
We introduce a noncommutative differential calculus on the two-parameter
-superplane via a contraction of the (p,q)-superplane. We manifestly show
that the differential calculus is covariant under
transformations. We also give a two-parameter deformation of the
(1+1)-dimensional phase space algebra.Comment: 14 page
Microbial dynamics during various activities in residential areas of Lahore, Pakistan
Bioaerosols are ubiquitous in the atmosphere with their levels affected by a variety of environmental factors as well as
type of activities being carried out at any specific time. The present study investigated how indoor activities influence
bioaerosol concentrations in five residential houses of Lahore. Agar coated petri plates were exposed face upwards for
twenty minutes in kitchens and living rooms during activity and non-activity periods. The temperature and relative
humidity levels were noted as well. The bioaerosol concentrations in kitchens during the activity time ranged between
1022 to 4481 cfu/m3 and in living rooms from 1179 to 3183 cfu/m3 . Lower values were observed during non-activity
periods. A paired-t test revealed a significant difference in bacterial loads during activity and non-activity times in both
micro-environments (p = 0.038 in kitchen and p = 0.021 in living room). The predominant species identified were
Micrococcus spp., Staphylococcus spp., and Bacillus spp. which are a common constituent of the indoor environment
and are known to be opportunistic pathogens as well
Temperature analysis of ZnO/p-Si heterojunction using thermionic emission model
Two ZnO/p-Si heterojunction diode structures are modeled based on thermionic emission in numerical computation environment, and their current-voltage characteristics were validated in Spice with 500 Ω and 5 kΩ load resistance. Both structures are differentiated based on thickness, metal size, and doping concentration. Parameters extracted such as barrier height, ideality factor, activation energy, series resistance, and shunt resistance are studied towards temperature-dependent study from 300 K to 673 K. Structure 1 proved to be exhibiting lower barrier height , series resistance and shunt resistance while structure 2 has lower ideality factor, activation energy, and turn on voltage. Modeling the ideality factor of structure 2 predicts a value of 0.25 at 673 K. Meanwhile, the turn on voltage of structure 2 is shown to achieve 0.8 V at room temperature. Barrier heights for structure 1 are reported to increase from 0.68 eV to 1.17 eV when temperature varies from 300 K to 673 K but series resistance and shunt resistance decreases with temperature
Anal incontinence after vaginal delivery or cesarean section.
INTRODUCTION: Uncertainties remain as to whether cesarean section is protective for short and long term development of anal incontinence. Our aim was to explore whether women who had only delivered vaginally were at greater risk of anal incontinence compared to nulliparous women and women who had undergone caesarean sections only. MATERIAL AND METHODS: Background information, medical history and data on anal incontinence (defined as fecal or flatus incontinence weekly or more) reported by women participating in a large population-based health survey in Norway (HUNT 3) during the period October 2006-June 2008, was collected and linked to data from the Medical Birth Registry of Norway. Anal incontinence prevalence was calculated and multivariable logistic regression analyses were applied. RESULTS: Mean age amongst the 12.567 women was 49.9 years. Age and educational level were similar in women with caesarean sections only and those with vaginal delivery and obstetric anal sphincter injuries (OASIS). Nulliparas and women with vaginal delivery and no OASIS were older and had higher educational achievements. One in four women with OASIS reported anal incontinence compared to one in six amongst the other women(p<.001). Age, educational level, diarrhea, constipation, birthweight and OASIS increased the risk of anal incontinence in all women. Parity was associated with anal incontinence in parous women only. No differences were found for fecal urgency. CONCLUSIONS: Women with vaginal deliveries complicated by OASIS were at increased risk of anal incontinence. However, no increased risk of anal incontinence was found in nulliparous women or women with cesarean sections only or vaginal deliveries not complicated by OASIS
Remote Sensing Of Turbidity Mapping From Digital Camera Imagery.
A complete set of normal digital camera data and ground-based measurements are used to test an algorithm for retrieval of turbidity distribution in the Prai Estuary, Penang, Malaysia
The effects of childbirth on the pelvic-floor
Basically, vaginal delivery is associated with the risk of pelvic floor damage. The pelvic floor sequelae of childbirth includes anal incontinence, urinary incontinence and pelvic organ prolapse. Pathophysiology, incidence and risk factors for the development of the respective problems are reviewed. Where possible, recommendations for reducing the risk of pelvic floor damage are given
Anatomical and Phytochemical Studies of the Leaves and Roots of Urginea grandiflora Bak. and Pancratium tortuosum Herbert
Urginea grandiflora Bak. and Pancratium tortuosum Herbert are bulbous, medicinal plants endemic to the Sudan. The aim of this study was to provide information on the anatomical properties of the leaves and roots of these two bulbous plants. Anatomical studies include cross sections of the leaves and roots. In addition, phytochemical screening methods were applied for identifying the major chemical groups in these species. This study provides referential botanical and phytochemical information for correct identification of these plants
Optimization of Cutting Parameters for Surfaces Roughness of Medium Carbon Steel C-45 in CNC Turning Machining by Using Taguchi Method
الهدف من هذه الدراسة هو الحصول على افضل متغيرات الة الخراطة الرقمية (CNC) و التي تعطى انعم نهاية لقطع مصنوعة من الصلب المتوسط الكربوني باستخدام عدة قطع كربيديه لديها مقاومة عالية لتأكل و الاحتكاك في وجود سوائل التبريد, وذلك لان نعومة السطح النهائية هي من أهم الخصائص المطلوبة للمنتج النهائي.
اعتمادا على دراسات أجريت حديثا فى العالم وجد ان عملية الخراطة الصلدة لها اكثر فائدة مقارنة بعملية التجليخ, نذكر منها نقص التكلفة في الوقت المستهلك في خراطة الاجزاء, فى هذه الدراسة, تأثير خشونة السطح على مقاومة الاحتكاك للخراطة الصلدة النهأية للمعدن المتوسط الكربون عمليا وتحليليا وكذلك البنية المجهرية تم التحقق منها. وللحصول على أفضل نهاية سطح تم استخـدام تصميم تاقوتشي (Taguchi method) لأفضل خراطة عملية معتمدا على تصميم المضروب الكلى لتحديد ثلاثة متغيرات مختلفة و مستويات باستخدام المصفوفات الثمانية, و تسع تجارب تم اجرائهاعمليا. تم اختيار ثلاث متغيرات وهى (معدل التغذية، سرعة القطع، عمق القطـع ) كانت مهمة, تم اختبار متغيرات القطع على النحو التالي: معدل التغذية (0.075, 0.10, 0.125 مم/لفة) سرعة القطع (166.24, 180.70, 197.32 ملم/دقيقة ) عمق القطع (2.0 ,2.5 , 3.0مم ) هذه المتغيرات اختيرت كما هو مطلوب من شركة ساندفك لتصنيع العدة(SANDVIC Tool Manufacturing Company ).
عمليات الخراطة العملية التي انجزت تم قياس خشونة السطح للقطع التي دُرست باستخـدام (MINITAB Statistical Software) و ذلك لحساب مؤشر (S/N) وكذلك تحليل التباين (ANOVA)، حيث تم الحصول على أفضل مستويات لأفضل متغيرات قطع و مدى تأثيرهـا على خشونة السطح , وكذلك متغيرات تجربة خشونة السطح كانت بمعدل تغدية (0.075 مم/لفة) وسرعة القطع (180.70ملم/دقيقة) وبعمق قطع (3.0 مم) و هذه تم الحصول عليها فى التجربة رقم خمسة (5). لتأكيد التجربة والحصول على المستوى الامثل لعملية التغيرات و التى اجريت لتحديد تـأثير كفاءة طريقة تاقوشى كأداة لقياس خشونة السطح.The objective of this study is to optimize the Computer Numerical Control machine (CNC) turning parameters that gives the fine surface finish for the parts that made of medium carbon steel C45 using carbide cutting tool (coated insert cemented carbide) which have high resistance of deflection, wear and fraction on CNC turning operation with coolant. The surface finish quality is one of the most specified requirements in the machining process.
To obtain the optimal surface finish, the Taguchi method used for optimization of the turning experiments based on a full factorial design, to determine three different parameters and levels by using orthogonal arrays, 9 experiments were obtained. Choice of three parameters (feed rate, cutting speed and depth of cut) were important, the cutting parameters were selected as follow: Feed rate (0.075, 0.100, 0.125mm), cutting speed (166.24, 180.70, 197.32 mm/min), depth of cut (0.5, 0.75, 1.0 mm) these parameters were chosen according to SANDVIC Tool Manufacturing Company. The series of turning experiments were performed to measure the surface roughness.
The MINITAB Statistical Software was used to calculate the signal-to-noise ratio (S/N), and analysis of the variance (ANOVA), the best optimal levels and the effect of the process parameters on surface roughness were obtained.
The parameters for experiment surface roughness were the feed (0.075mm/rev), cutting speed (180.70 mm/min), depth of cut (3.0mm) and that conducted in experiment number five (5).
A conformation of experiment to obtained optimal levels of process parameters was carried out in order to demonstrate the effectiveness and efficiency of the employed Taguchi method as a tool to measure surface roughness.  
- …