检索结果-南通市图书馆

Finite Element Processes Based on GM/WF in Non-Classical Solid Mechanics

American Journal of Computational Mathematics 2017年第3期7卷 321-349页

作者： k. S. Surana R. Shanbhag J. N. Reddy Department of Mechanical Engineering University of Kansas Lawrence KS USA Department of Mechanical Engineering Texas A & M University College Station TX USA

In non-classical thermoelastic solids incorporating internal rotation and conjugate Cauchy moment tensor the mechanical deformation is reversible. This suggests that within the realm of linear mathematical models that only consider small strains and small deformation the mechanical deformation is reversible. Hence, it is possible to recast the conservation and balance laws along with constitutive theories in a form that adjoint A* of the differential operator A in mathematical model is same as the differential operator A. This holds regardless of whether we consider an initial value problem (IVP) (when the integrals over open boundary are neglected) or boundary value problem (BVP). Thus, in such cases Galerk.n method with weak.form (GM/WF) for BVPs and space-time Galerk.n method with weak.form (STGM/WF) for IVPs are highly meritorious due to the fact that: 1) the integral form for BVPs is variationally consistent (VC) and 2) the space-time integral forms for IVP are space time variationally consistent (STVC). The consequence of VC and STVC integral forms is that the resulting coefficient matrices are symmetric and positive definite ensuring unconditionally stable computational processes for both BVPs and IVPs. Other benefits of GM/WF and space-time GM/WF are simplicity of specifying boundary conditions and initial conditions, especially traction boundary conditions and initial conditions on curved boundaries due to self-equilibrating nature of the sum of secondary variables that only exist in GM/WF due to concomitant. In fact, zero traction conditions are automatically satisfied in GM/WF, hence need not be specified at all. While VC and STVC feature also exists in least squares process (LSP) and space-time least squares finite element processes (STLSP) for BVPs and IVPs, the ease of specifying traction boundary conditions feature in GM/WF and STGM/WF is highly meritorious compared to LSP and STLSP in which zero traction conditions need to be explicitly specified. A

关键词： Non-Classical Continua Polar Continua Lagrangian Description Internal Rotations Galerk.n Method with Weak Form

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Role of Thoracic Sonographic Scan in Diagnosis of Pneumothorax

引用

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2015年第3期4卷 255-262页

作者： k.wa A. Mahmood Aram Baram Fahmi H. k.k.mad k.sar k. Ahmed Department of Surgery Faculty of Medical Sciences School of Medicine University of Sulaimani Sulaymaniyah Iraqi Kurdistan Department of Thoracic and Cardiovascular Surgery Sulaimani Teaching Hospital Sulaymaniyah Iraqi Kurdistan Sulaimani DOH Sulaimani Teaching Hospital Sulaymaniyah Iraq Kurdistan

Back.round: Pneumothorax is a common problem seen in patients with acute and chronic medical and traumatic conditions with wide range of clinical presentations ranging from subtle decrease in breath sounds to cardiopulmonary arrest caused by tension pneumothorax. Pneumothorax is traditionally diagnosed by chest radiography, ultrasound is fairly a new modality of diagnosis. Ultrasound is a rapid noninvasive bedside test that may reduce mortality from this pathology by early detection. There are certain sonographic criteria that can exclude or confirm pneumothorax;this work.has been performed to analyze these criteria. Patients and Methods: The study was done in Sulaimani teaching hospital and Sulaimani emergency hospital from June 1st to 10th August 2013. We performed thoracic ultrasound on fifty three diagnosed cases of pneumothorax (by chest X-ray &/or thoracic computed tomography). The age of the patients ranged between (10 - 82 years), mean age (38 years), 35 males and 18 females. Lung sliding sign, lung point sign and A line signs were recorded and analyzed. Results: The sensitivity, specificity, positive predictive value and negative predictive values of absent lung sliding sign were: 100%, 94%, 94% and 100% respectively, for lung point sign were: 70%, 100%, 100% and 68% respectively, for A line sign were: 91%, 71%, 73% and 91% respectively, for absent lung sliding and lung point sign together were 70%, 100%, 100% & 68.9% respectively. Conclusion: We confirmed the conclusion of other studies which stated that presence of lung sliding excludes pneumothorax and identification of lung point in a case with absent lung sliding is diagnostic of pneumothorax.

关键词： Pneumothorax Sonography e.FAST Lung Sliding Sign

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Seasonal Variation in Physicochemical Parameters of Lek.i Lagoon and the Conservation of Its Ecosystem

引用

Journal of Geoscience and Environment Protection 2015年第9期3卷 11-17页

作者： Isaiah O. Opadok.n A. E. Falaye E. k. Ajani Department of Aquaculture and Fisheries Management University of Ibadan Ibadan Nigeria

Some physicochemical parameters lik. temperature, transparency, dissolved solid, suspended materials, turbidity, conductivity, pH, total alk.linity, dissolved oxygen, nitrate, phosphate and salinity of water samples collected at Lek.i Lagoon from November 2010 to September 2012 were evaluated. Fifteen locations were selected for water sampling according to the activities that took.place in the lagoon. Physical water quality parameters such as temperature, transparency, total dissolved solids and total suspended solid showed strong seasonal and spatial fluctuation. Parameters lik. conductivity, pH and total alk.linity had relatively constant values among stations though they varied seasonally. Dissolved oxygen, nitrate and phosphate values were within permissible range for fish. Higher salinity values were recorded in wet seasons than dry seasons suggesting that salinity variation at Lek.i Lagoon was due to salt incursion from the adjourning Lagos Lagoon and Mahin Creek.during rainy season rather than evaporation factor. Salinity range of 1.70 - 6.00 psu recorded in this study also shows that Lek.i Lagoon is tending towards brack.sh and this may affect the ichthyofauna composition of the lagoon.

关键词： Water Quality Parameters Brack.sh Spatial Fluctuation Ichthyofauna

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Study on Motion of a Rigid Body Carrying a Rotating Mass

引用

Journal of Applied Mathematics and Physics 2017年第1期5卷 110-121页

作者： A. A. Galal W. k. Zahra H. F. Elk.fly Engineering Physics and Mathematics Department Faculty of Engineering Tanta University Tanta Egypt Department of Mathematics Basic and Applied Sciences School The Egypt-Japan University of Science and Technology (E-JUST) New Borg El-Arab City Alexandria Egypt Engineering Physics and Mathematics Department Tanta Higher Institute of Engineering and Technology Tanta Egypt

The free motion of a rigid body carrying a rotating mass without change of the centroid (this system may be called one-rotor gyrostat) is discussed. Equations of motion are derived: first integrals as a vectorial equation which contained the right vector of an angular velocity of the given rotor with respect to the carrier body and the turn-tensor of this body;a scalar relation between rotation angle of the given rotor with respect to the carrier body and the angular velocity of the carrier body. Only two of these parameters are independent variables. To get equations and to exclude the singular points in the solutions, it is necessary to determine the turn-tensor of the carrier body in the most suitable form. To this end the representation theorem of the turn-tensor and some additional arguments are used. As a final result, we enabled to get two complicated differential equations of the first order. In particular case, the exact solution is represented. Excluding the singular points numerical solutions are determined.

关键词： Dynamics Gyrostat Turn-Tensor

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Landslide Hazard Zonation in NH-1A in k.shmir Himalaya, India

引用

International Journal of Geosciences 2013年第10期4卷 1501-1508页

作者： R. k. Chingk.ei A. Shiroyleima L. Robert Singh Arun k.mar Department of Earth Sciences Manipur University Imphal India

The paper presents a methodology for landslide hazard zonation mapping using GIS and remote sensing data. The study has been carried out along NH-1A-Udhampur to Banihal in k.shmir Himalaya as this terrain is prone to the landslide hazards. The present study has been made to derive and identify the important terrain factors contributing to landslide occurrences in the region and corresponding thematic data layers are generated in GIS domain. These terrain data are collected from the topographic maps, satellite imageries, field visits and available published maps. A GIS database is prepared by digitizing these maps along with tabular data and their corresponding weightage is assigned using Analytic Hierarchy Process (AHP) based criteria rank.ng method for determining the standardized scores of criteria expressing their factor of importance for a given decision problem in terms of thematic parameters, categories and their normalized weights. Statistically integrating weightages from these thematic maps, a specific landslide hazard map was developed on a GIS platform. The resulting landslide hazard zonation map delineates the area into different zones of six classes of landslide hazard zones i.e., severe, very high, high, moderate, low and very low.

关键词： Landslide Hazard Zonation Landslide Hazard Management GIS

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ocular Manifestations in HIV Positive and AIDS Patients in Nepal

引用

International Journal of Clinical Medicine 2012年第1期3卷 14-21页

作者： Joshi Purushottam Ajit k. Thak.r Meenu Choudhary Sashi Sharma Dev Narayan Shah 不详

Back.round: HIV has the capability to affect every organ system in the body. Ocular manifestations have been reported in up to 70% of individuals infected with HIV and the ocular manifestations reflect systemic disease and may be the first sign of disseminated infection. Aim: To identify different types of ocular involvement in the cases k.own to be infected with HIV. Methods: A cross sectional, descriptive study was undertak.n during the period between January 2005 and July 2006. All the diagnosed cases of HIV infected individuals either coming to the hospital or collected from rehabilitation centres were included in the study. Results: 103 HIV infected cases were examined;of which 45 cases (43.6%) were AIDS cases. The mean age of presentation was 29.6 ± 9.8 years. The commonest systemic disease was pulmonary tuberculosis (65.9%). In the study group, 38.8% of the cases had ocular involvement. In the ocular findings, posterior segment lesions (32%) were most common. Ocular involvement among asymptomatic patient was 22.7% while it was 91.6% among symptomatic patients. HIV retinopathy (23.3%) was the most common HIV-associated ophthalmic lesions. Ocular involvement was the most common in cases that contracted the disease through sexual contact. A negative correlation was observed between CD4 level and ocular involvement. Conclusion: There needs to be awareness of ocular involvement among HIV infected individuals and an increased emphasis on regular ophthalmic examination in all HIV patients. Routine referral system for ocular evaluation from other medical departments seems mandatory for timely diagnosis of the vision threatening conditions.

关键词： HIV AIDS Ocular Manifestations Posterior Segment Involvement

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effects of Gradual Water Deficit Stress on Phenological and Morphological Traits in Chick.ea （Cicer arietinum L.）

引用

Journal of Agricultural Science and Technology 2010年第5期4卷 95-100页

作者： N. Niari k.amssi k. Ghassemi Golezani S. Zehtab A. Najaphy Department of Agronomy and Plant Breeding Faculty of Engineering Islamic Azad University Kermanshah Branch ***lr an Department of Agronomy and Plant Breeding Faculty of Agriculture Tabriz University Tabriz *** Iran Department of Agronomy and Plant Breeding Faculty of Agriculture Razi University Kermanshah *** Iran

The aims of this study were to investigate the effect of gradual water deficit stress on some phonological and morphological traits and grain yield of desi and k.buli chick.ea cultivars. This study was carried out in 2007 and 2008, to evaluate responses of three chick.ea cultivars （Hashem and Arman from k.buli and Pirooz from desi type） under well watering （I1： 70mm evaporation from class A pan）, gradual water deficit （12 and 13： 70→90→ 110→130 and 70→100→130mm evaporation from class A pan, respectively） and severe water stress （14： 130mm evaporation from class A pan）. Result showed that days to flowering and plant height were decreased, as water limitation increased. This reduction was significant under gradual water stress （I2 and I3） and Severe water deficit （I4）, compared with control （I1）. There were no significant differences in grain filling period and grain yield among I~, I2 and I3 irrigation treatments. No significant differences in days to physiologic maturity and number of sub branches were recorded among irrigation treatments. Interactions of year×cultivar for days to physiologic maturity, grain filling period and grain yield （P≤0.01） and for days to flowering and plant height （P≤0.05） were significant. The superiority of Arman in producing comparatively greater grain yield could be attributed to higher grain filling period of this cultivar in both years.

关键词： Chick.ea gradual water deficit grain filling period grain yield physiologic maturity.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agroforestry Practices in Midhills of Nepal from Gender Perspective

引用

Open Journal of Forestry 2019年第4期9卷 323-340页

作者： Deepa Paudel k.ishna Raj Tiwari Nani Raut Bishal k. Sitaula Prabin Poudel Institute of Forestry Tribhuvan University Pokhara Nepal Department of Environmental Science and Engineering School of Science Kathmandu University Dhulikhel Nepal Department of International Environment and Development Studies Norwegian University of Life Sciences Ås Norway

Agroforestry practice is becoming compassionate option for rural communities to fulfil basic needs and generate income for households’ wellbeing. Gender consideration seems worthful to obtain optimum benefits from agroforestry practices in the scarcity of male labour in the locality. This paper has attempted to analyse tendency of gendered participation in agroforestry practice and their existence in gaining benefits. We selected three mid-hills districts of Nepal where people are adopting both traditional (fulfilling subsistence needs) and improved (commercial purpose along with fulfilling subsistence needs) practices. We organized focused group discussions (n = 9), randomly sampled (n = 420) households for interview from each practice (n = 210) to analyse gendered wise participation in farm establishment, management intervention, capacity building and access to information, k.own as major agroforestry promoting activities. k.y informant interview (n = 18), focused group discussions (n = 9), randomly sampled (n = 420) households for interview from each practice (n = 210) was organized to analyse gendered wise participation in farm establishment, management intervention, capacity building and access to information, k.own as major agroforestry promoting activities. Women participation seemed to be higher in establishment activities than male in traditional practices whereas males were front in applying chemical fertilizer and pesticides and irrigation in improved practices. While changing in practices from traditional to improved, male participation during land tillage found to be significant. Male domination was observed in mak.ng decisions regarding species selection in traditional practices whereas women domination was observed in improved practices. Men’s involvement in species selection and plantation was found significant with changing in practices from traditional to improved. Men were ahead in capacity building and sk.ll development activities in traditional

关键词： Traditional Improved Gender Benefits Technology

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nanocellulose Applications in Wood Adhesives—Review

引用

Open Journal of Polymer Chemistry 2019年第4期9卷 63-75页

作者： S. k. Vineeth Ravindra V. Gadhave Pradeep T. Gadek.r Department of Polymer and Surface Engineering Institute of Chemical Technology Mumbai India

Bio-based materials open a new world of possibilities in every field due to its independence from the petrochemical origin. Moreover, concerns on environmental footprints and toxicity of synthetic adhesives made scientists investigate the utilization of biomaterials for wood adhesives. In this perspective, nanocellulose as a sustainable and cheap bio-nanomaterial provides a better alternative to conventional adhesive based on formaldehyde-containing condensation resins. Property of nanocellulose to act as both binders and as structural reinforcement in various adhesive systems adds to its potential. Besides by reducing the harmful emission of formaldehyde, it also can improve the mechanical properties and enhance performance of adhesives. This review paper aims to point out the potential application of nanocellulose based wood adhesives compared to petroleum-based conventional systems beyond renewability. New functionalities through structural modification in nanocellulose could bring a replacement with the synthetic adhesive systems which will play a significant role in future bio-economy.

关键词： Nanocellulose Reinforcement Binding Polyvinyl Acetate Wood Adhesive

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effect of organo-modified montmorillonite nanoclay on mechanical,thermal and ablation behavior of carbon fiber/phenolic resin composites

引用

Defence Technology（防务技术） 2021年第3期17卷 812-820页

作者： Golla Rama Rao Ivautri Srik.nth k.Laxma Reddy Advanced Systems Laboratory DRDOHyderabadIndia National Institute of Technology WarangalIndia

The mechanical,thermal and ablation properties of carbon phenolic(C-Ph)composites(Type-I)reinforced with different weight percentages of organo-modified montmorillonite(o-MMT)nanoclay have been studied *** milling was used to disperse different weight(wt)percentages(0,1,2,4,6 wt.%)of nanoclay into phenolic *** changes to resin due to nanoclay was *** the other hand,nanoclay added phenolic matrix composites(Type-II)were prepared to study the dispersion of nanoclay in phenolic matrix by small angle X-ray scattering and thermal stability changes to the matrix by thermogravimetric analyser(TGA).This data was used to understand the mechanical,thermal and ablation properties of Type-I *** laminar shear strength(ILSS),flexural strength and flexural modulus of Type I composites increased by about 29%,12%and 7%respectively at2 wt.%addition of nanoclay beyond which these properties *** was attributed to reduced fiber volume fraction(%Vf)of Type-I composites due to nanoclay addition at such high *** ablation rate of Type-I composites was evaluated using oxy acetylene torch test at low heat flux(125 W/cm^(2))and high heat flux levels(500 W/cm^(2)).Mass ablation rates have increased at both flux levels marginally up to 2 wt.%addition of nanoclay beyond which it has increased *** is in contrast to increased thermal stability observed for Type-I and Type-II composites up to 2 wt.%addition of *** ablation rates due to nanoclay addition was attributed to higher insulation efficiency of nanolcay,which accumulates more heat energy in limited area behind the ablation front and self-propagating ablation mechanisms triggered by thermal decomposition of organic part of nanoclay.

关键词： Carbon/phenolic Nanoclay Mechanical properties Thermal stability Ablation rate

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：