A closed form for the electrostatic interaction between two rod-like charged objects

We have calculated the electrostatic interaction between two rod-like charged objects with arbitrary orientations in three dimensions. we obtained a closed form formula expressing the interaction energy in terms of the separation distance between the centers of the two rod-like objects, $r$, their lengths (denoted by $2l_1$ and $2l_2$), and their relative orientations (indicated by $\theta$ and $\phi$). When the objects have the same length ($2l_1=2l_2=l$), for particular values of separations, i.e for $r\leq0.8 l$, two types of minimum are appeared in the interaction energy with respect to $\theta$. By employing the closed form formula and introducing a scaled temperature $t$, we have also studied the thermodynamic properties of a one dimensional system of rod-like charged objects. For different separation distances, the dependence of the specific heat of the system to the scaled temperature has been studied. It is found that for $r<0.8 l$, the specific heat has a maximum.Comment: 10 pages, 9 figures, 1 table, Accepted by J. Phys.: Condens. Matte

KLINIČKE PRIČE I MEDICINSKE ANAMNEZE KOJE JE ZABILJEŽIO RHAZES (865.–925.), IRANSKO‑ISLAMSKI LIJEČNIK SREDNJEGA VIJEKA

Recording medical histories of patients is not a new issue in clinical medicine. However, the method practiced by the Iranian chemist physician, Rhazes, in the ninth century A.D is incredible. Rhazes has written several textbooks in clinical medicine, but a particular one, “Clinical Stories and Medical Histories” (Qesas va hekayat al-marazi), is a classical case book describing precise clinical courses of thirty three patients. Each chapter includes a title, the name and demographic data about a patient, his/her history of present illness, past medical and family history, findings of physical exam, impression and interventions by the physician, including pharmacological or surgical management. The reasons for each decision made by Rhazes as well as the outcomes are clearly discussed. This book review will shed light on the unknown medical practice methods in Islamic-Iranian golden era.Bilježenje medicinske anamneze pacijenata nije novo pitanje kliničke medicine. Kako bilo, metoda koju je prakticirao Rhazes, iranski kemičar i liječnik, u devetom stoljeću zadivljujuća je. Rhazes je napisao nekoliko udžbenika iz kliničke medicine, ali ona kratka, Kliničke priče i medicinske anamneze, klasična je knjiga prikaza slučajeva koja opisuje točan klinički tijek kod trideset i tri pacijenta. Svako poglavlje uključuje naslov, ime i demografske podatke o pacijentu, njenu/njegovu povijest trenutne bolesti, prošlu medicinsku i obiteljsku povijest bolesti, nalaze fizikalnog pregleda, utiske i intervencije liječnika, uključujući farmakološke i/ili kirurške postupke. Razlozi su svake Rhazesove odluke kao i rezultati jasno raspravljeni. Čitanje zabilješki u ovoj knjizi pomaže osvijetliti nepoznate kutke koji se tiču metoda medicinskih praksi u vrijeme rađanja islamskoiranske civilizacije

Relative growth of the fiddler crab, Uca sindensis(Crustacea: Ocypodidae) in a subtropical mangrove in Pohl Port, Iran

The relative growth of the fiddler crab Uca sindensis in Pohl Port was studied. Ten 0.5 m^2 quadrates were randomly sampled monthly during low tide periods from October 2009 to September 2010. A total of 840 crabs, 449 (53.45%) males and 391 (46.5%) ‌ females, were sampled. The Carapace width of males ranged from 5.5 to 13.5 mm (mean ± SD) (8.92 ± 2.04), and of females from 5.0 to 11.5 mm (mean ± SD) (7.95 ± 1.34). Carapace height (CH) and Carapace length (CL), height of the major cheliped (HMC) of males, abdomen width of females (AW), major cheliped length (LMC), dactiluse (D), feeding cheliped (CHF) and merouse (M) were employed as dependent variables and carapace width (CW) as independent variable. The relationship between CW × CH was positive in males and females. The equation (Log CH=Log-4.881+4.681LogCW) for males (P<0.05) and Log CH=Log-1.882+3.299LogCW for females (P<0.05). The females showed allometric positive growth for CW × AW relation to male (Log AW= Log0.784+1.217Log CW) (P<0.05). Also four male crabs were found with two major cheliped in this study. Remarkable ontogenetic changes were observed in the allometric growth of the male major cheliped and the female abdomen, indicating that these structures are closely connected to the timing of sexual maturity. The allometric growth of U. sindensis in Pohl Port mangrove differed from other Uca populations so far studied, indicating that growth could have been influenced by environment variables such as food availability, population density, distribution of vegetation, sex ratio, soil temperature , organic matter, different of surface and sediment

A Test Collection of Synthetic Documents for Training Rankers:ChatGPT vs. Human Experts

We investigate the usefulness of generative large language models (LLMs) in generating training data for cross-encoder re-rankers in a novel direction: generating synthetic documents instead of synthetic queries. We introduce a new dataset, ChatGPT-RetrievalQA, and compare the effectiveness of strong models fine-tuned on both LLM-generated and human-generated data. We build ChatGPT-RetrievalQA based on an existing dataset, the human ChatGPT comparison corpus (HC3), consisting of multiple public question collections featuring both human- and ChatGPT-generated responses. We fine-tune a range of cross-encoder re-rankers on either human-generated or ChatGPT-generated data. Our evaluation on MS MARCO DEV, TREC DL'19, and TREC DL'20 demonstrates that cross-encoder re-ranking models trained on LLM-generated responses are significantly more effective for out-of-domain re-ranking than those trained on human responses. For in-domain re-ranking, however, the human-trained re-rankers outperform the LLM-trained re-rankers. Our novel findings suggest that generative LLMs have high potential in generating training data for neural retrieval models and can be used to augment training data, especially in domains with less labeled data. ChatGPT-RetrievalQA presents various opportunities for analyzing and improving rankers with both human- and LLM-generated data. Our data, code, and model checkpoints are publicly available.</p

Can excessive wear of ceramic bearing couples be a consequence of hip squeaking?

The occurrence of Ceramic-­on­‐Ceramic hip squeaking in some patients is a cause for concern. Friction was shown the main reason of hip squeaking. Moreover, hip vibration significantly altered contact point path during the gait cycle. This study investigated the effect of hip squeaking on hip implant wear

Nonlinear free vibration analysis of the functionally graded beams

Nonlinear natural oscillations of beams made from functionally graded material (FGM) are studied in this paper. The equation of motion is derived according to the EulerBernoulli beam theory and von Karman geometric nonlinearity. Subsequently, Galerkin’s solution technique is applied to obtain the corresponding ordinary differential equation (ODE) for the FGM beam. This equation represents a kind of a nonlinear ODE containing quadratic and cubic nonlinear terms. This nonlinear equation is then solved by means of three efficient approaches. Homotopy perturbation method is applied at the first stage and the corresponding frequency-amplitude relationship is obtained. Frequency-amplitude formulation and Harmonic balance method are then employed and the consequent frequency responses are determined. In addition, Parameter Expansion Method is utilized for evaluating the nonlinear vibration of the system. A parametric study is then conducted to evaluate the influence of the geometrical and mechanical properties of the FGM beam on its frequency responses. Different types of material properties and boundary conditions are taken into account and frequency responses of the system are evaluated for different gradient indexes. The frequency ratio (nonlinear to linear natural frequency) is obtained in terms of the initial amplitude and compared for different materials and end conditions

Socio-demographic and built environment determinants of car use among older adults in Iran

Internationally, an age-friendly built environment, including safe, affordable, and convenient transportation, has been identified as crucial in enhancing the quality of life for increasingly large numbers of elderly people. This study presents data on the urban travel and mobility patterns of older adults in Shiraz, Iran – a country where the population is ageing faster than the average of western societies. The relationship between car use and socio-demographic and built environment variables is investigated through Ordinary Least Squares and Geographically Weighted Regression models. These models show that the main determinants of car use among older adults are: employment status; household size; car ownership rate; trip purpose; property prices; and mixed land-uses. Also, the study reveals that car dependency is significant and more pronounced among wealthier individuals, who tend to be clustered in the northern section of the city. The population density and road network design characteristics do not affect car use among older adults, while a mix of land-uses tends to attenuate car dependency. Gender gaps in car use are much wider than in the West, and some level of spatial mismatch between travel needs and car access is observed in the southern section of the city. Clearly, Iranian cities must move away from the current car-centric development model

Our experience with van nes rotationplasty for locally advanced lower extremity tumours

Abstract OBJECTIVE: To present an early experience with the time-tested technique of Van Ness Rotationplasty to save distal lmbs. METHODS: Van Nes Rotationplasty for locally advanced lower extremity tumours. A reterorespective audit was conducted at Aga Khan University Hospital, Karachi, and comprised cases of bone and soft tissue sarcoma who underwent Van Ness Rotationplasty over seven years from January 2005 to December 2011. Demographic data, family history, past history, co-morbids, date since diagnosis, duration of symptoms, type of tumour, metastasis, pre-op and post-op functional status, recurrence and survival were collected. RESULTS: Of the 351 cases of bone and soft tissue sarcoma, 9 (2.6%) underwent Van Ness Rotationplasty and were included in the study. The mean duration of symptoms was 7±3SD months (range: 8-41 months). All except 1(11.1%) were osteogenic sarcomas. All except 1(11.1%) involved distal femur. Overall, 7(77.8%) had localised Enneking stage IIB disease. Two (22.2%) patients expired due to metastatic disease, but none had local recurrence. Complete excision of tumour was achieved in all (100%) patients. Longest follow-up was of 34 months while the shortest was of 6 months. No local recurrences were noted. Functional recovery was good. Two (22.2%) patients had simultaneous sciatic nerve repair as part of the primary procedure. Both of them had good motor function at the time of final follow-up. Mean Musculoskeletal Tumour Societyscore was 23.88±2SD. CONCLUSIONS: Van Nes Rotationplasty was found to be a successful alternative to amputation in cases of locally advancedtumours of distal femur or proximal tibia

Production Scheduling and Waste Disposal Planning for Oil Sands Mining Using Goal Programming

In oil sands mining, timely provisions of ore and tailings containment with less environmental footprints are the main drivers of profitability and sustainability. The recent Alberta Energy Resources Conservation Board Directive 074 requires oil sands waste disposal planning to be an integral part of mine planning. This requires the development of a well integrated strategy of directional mining and tailings dyke construction for in-pit and ex-pit tailings storage management. The objectives of this paper are to: 1) determine the order and time of extraction of ore, dyke material and waste that maximizes the net present value; 2) determine the destination of dyke material that minimizes construction cost; and 3) minimize deviations from the production goals of the mining operation. We have developed, implemented, and verified a theoretical optimization framework based on mixed integer linear goal programming (MILGP) to address these objectives. This study presents an integration of mixed integer linear programming and goal programming in solving large scale mine planning optimization problems using clustering and pushback techniques. Application of the MILGP model was presented with an oil sands mining case. The MILGP model generated a smooth and uniform mining schedule that generates value and provides a robust framework for effective waste disposal planning. The results show that mining progresses with an ore to waste ratio of 1:1.5 throughout the mine life, generating an overall net present value of $14,237M. This approach improves the sustainable development of oil sands through better waste management

CLosER: Conversational Legal Longformer with Expertise-Aware Passage Response Ranker for Long Contexts

In this paper, we investigate the task of response ranking in conversational legal search. We propose a novel method for conversational passage response retrieval (ConvPR) for long conversations in domains with mixed levels of expertise. Conversational legal search is challenging because the domain includes long, multi-participant dialogues with domain-specific language. Furthermore, as opposed to other domains, there typically is a large knowledge gap between the questioner (a layperson) and the responders (lawyers), participating in the same conversation. We collect and release a large-scale real-world dataset called LegalConv with nearly one million legal conversations from a legal community question answering (CQA) platform. We address the particular challenges of processing legal conversations, with our novel Conversational Legal Longformer with Expertise-Aware Response Ranker, called CLosER. The proposed method has two main innovations compared to state-of-the-art methods for ConvPR: (i) Expertise-Aware Post-Training; a learning objective that takes into account the knowledge gap difference between participants to the conversation; and (ii) a simple but effective strategy for re-ordering the context utterances in long conversations to overcome the limitations of the sparse attention mechanism of the Longformer architecture. Evaluation on LegalConv shows that our proposed method substantially and significantly outperforms existing state-of-the-art models on the response selection task. Our analysis indicates that our Expertise-Aware Post-Training, i.e., continued pre-training or domain/task adaptation, plays an important role in the achieved effectiveness. Our proposed method is generalizable to other tasks with domain-specific challenges and can facilitate future research on conversational search in other domains.</p