scholarly journals A downward buoyant force experiment

Author(s):  
F.M.S. Lima ◽  
G.M. Venceslau ◽  
G.T. Brasil

In hydrostatics, the Archimedes principle predicts an upward force whenever a body is submerged in a liquid. In contrast to common sense, this physical law is not free of exceptions, as for example when the body touches the container. This is more evident when a rectangular block less dense than the liquid rests on the bottom, with no liquid underneath it, a case in which a downward force is expected, according to a recent work by the first author. In the present work, we describe a simple, low-cost experiment which allows the detection of such force. This counterintuitive result shows the inadequacy of Archimedes' principle for treating "contact" cases.

Author(s):  
Luna Dolezal

The notion that the body can be changed at will in order to meet the desires and designs of its ‘owner’ is one that has captured the popular imagination and underpins contemporary medical practices such as cosmetic surgery and gender reassignment. In fact, describing the body as ‘malleable’ or ‘plastic’ has entered common parlance and dictates common-sense ideas of how we understand the human body in late-capitalist consumer societies in the wake of commercial biotechnologies that work to modify the body aesthetically and otherwise. If we are not satisfied with some aspect of our physicality – in terms of health, function or aesthetics – we can engage with a whole variety of self-care body practices – fashion, diet, exercise, cosmetics, medicine, surgery, laser – in order to ‘correct’, reshape or restyle the body. In addition, as technology has advanced and elective cosmetic surgery has unapologetically entered the mainstream, the notion of the malleable body has become intrinsically linked to the practices and discourses of biomedicine and, furthermore, has become a significant means to assert and affirm identity.


2021 ◽  
Vol 13 (5) ◽  
pp. 2836
Author(s):  
Khawar Shahzad ◽  
Muhammad Sultan ◽  
Muhammad Bilal ◽  
Hadeed Ashraf ◽  
Muhammad Farooq ◽  
...  

Poultry are one of the most vulnerable species of its kind once the temperature-humidity nexus is explored. This is so because the broilers lack sweat glands as compared to humans and undergo panting process to mitigate their latent heat (moisture produced in the body) in the air. As a result, moisture production inside poultry house needs to be maintained to avoid any serious health and welfare complications. Several strategies such as compressor-based air-conditioning systems have been implemented worldwide to attenuate the heat stress in poultry, but these are not economical. Therefore, this study focuses on the development of low-cost and environmentally friendly improved evaporative cooling systems (DEC, IEC, MEC) from the viewpoint of heat stress in poultry houses. Thermodynamic analysis of these systems was carried out for the climatic conditions of Multan, Pakistan. The results appreciably controlled the environmental conditions which showed that for the months of April, May, and June, the decrease in temperature by direct evaporative cooling (DEC), indirect evaporative cooling (IEC), and Maisotsenko-Cycle evaporative cooling (MEC) systems is 7–10 °C, 5–6.5 °C, and 9.5–12 °C, respectively. In case of July, August, and September, the decrease in temperature by DEC, IEC, and MEC systems is 5.5–7 °C, 3.5–4.5 °C, and 7–7.5 °C, respectively. In addition, drop in temperature-humidity index (THI) values by DEC, IEC, and MEC is 3.5–9 °C, 3–7 °C, and 5.5–10 °C, respectively for all months. Optimum temperature and relative humidity conditions are determined for poultry birds and thereby, systems’ performance is thermodynamically evaluated for poultry farms from the viewpoint of THI, temperature-humidity-velocity index (THVI), and thermal exposure time (ET). From the analysis, it is concluded that MEC system performed relatively better than others due to its ability of dew-point cooling and achieved THI threshold limit with reasonable temperature and humidity indexes.


2020 ◽  
pp. 1-15
Author(s):  
Kenneth W. Yu

How to inculcate virtue in the citizens of Magnesia by means of the dance component of choreia constitutes one of the principal concerns in the Laws (= Leg.), revealing Plato's evolving ideas about the expediency of music and paideia for the construction of his ideal city since the Republic. Indeed, a steady stream of monographs and articles on the Laws has enriched our understanding of how Plato theorizes the body as a site of intervention and choral dance as instrumental in solidifying social relations and in conditioning the ethical and political self. As one scholar has aptly put it: ‘a city and its sociopolitical character [are] effectively danced into existence.’ Drawing on this recent work, I focus on an enigmatic passage in Laws Book 7 that merits more attention than it has received, in which Plato curiously singles out Bacchic dances from those that are ‘without controversy’ (815b7–d4): τὴν τοίνυν ἀμφισβητουμένην ὄρχησιν δεῖ πρῶτον χωρὶς τῆς ἀναμφισβητήτου διατεμεῖν. τίς οὖν αὕτη, καὶ πῇ δεῖ χωρὶς τέμνειν ἑκατέραν; ὅση μὲν βακχεία τ᾽ ἐστὶν καὶ τῶν ταύταις ἑπομένων, ἃς Νύμφας τε καὶ Πᾶνας καὶ Σειληνοὺς καὶ Σατύρους ἐπονομάζοντες, ὥς φασιν, μιμοῦνται κατῳνωμένους, περὶ καθαρμούς τε καὶ τελετάς τινας ἀποτελούντων, σύμπαν τοῦτο τῆς ὀρχήσεως τὸ γένος οὔθ᾽ ὡς εἰρηνικὸν οὔθ᾽ ὡς πολεμικὸν οὔθ᾽ ὅτι ποτὲ βούλεται ῥᾴδιον ἀφορίσασθαι: διορίσασθαι μήν μοι ταύτῃ δοκεῖ σχεδὸν ὀρθότατον αὐτὸ εἶναι, χωρὶς μὲν πολεμικοῦ, χωρὶς δὲ εἰρηνικοῦ θέντας, εἰπεῖν ὡς οὐκ ἔστι πολιτικὸν τοῦτο τῆς ὀρχήσεως τὸ γένος, ἐνταῦθα δὲ κείμενον ἐάσαντας κεῖσθαι, νῦν ἐπὶ τὸ πολεμικὸν ἅμα καὶ εἰρηνικὸν ὡς ἀναμφισβητήτως ἡμέτερον ὂν ἐπανιέναι. So, first of all, we should separate questionable dancing far from dancing that is without controversy. Which is the controversial kind, and how are the two to be distinguished? All the dancing that is of a Bacchic kind and cultivated by those who indulge in intoxicated imitations of Nymphs, Pans, Sileni and Satyrs (as they name them), when performing certain rites of expiation and initiation—this entire class of dancing cannot easily be marked off either as pacific or as warlike, nor as of any one particular kind. The most correct way of defining it appears to me to be this—to place it away from both pacific and warlike dancing, and to pronounce that this type of dancing is οὐ πολιτικόν; having thus set aside and dismissed it, we will now return to the warlike and pacific types, which without controversy belong to us.


Author(s):  
Yang Gao ◽  
Yincheng Jin ◽  
Jagmohan Chauhan ◽  
Seokmin Choi ◽  
Jiyang Li ◽  
...  

With the rapid growth of wearable computing and increasing demand for mobile authentication scenarios, voiceprint-based authentication has become one of the prevalent technologies and has already presented tremendous potentials to the public. However, it is vulnerable to voice spoofing attacks (e.g., replay attacks and synthetic voice attacks). To address this threat, we propose a new biometric authentication approach, named EarPrint, which aims to extend voiceprint and build a hidden and secure user authentication scheme on earphones. EarPrint builds on the speaking-induced body sound transmission from the throat to the ear canal, i.e., different users will have different body sound conduction patterns on both sides of ears. As the first exploratory study, extensive experiments on 23 subjects show the EarPrint is robust against ambient noises and body motions. EarPrint achieves an Equal Error Rate (EER) of 3.64% with 75 seconds enrollment data. We also evaluate the resilience of EarPrint against replay attacks. A major contribution of EarPrint is that it leverages two-level uniqueness, including the body sound conduction from the throat to the ear canal and the body asymmetry between the left and the right ears, taking advantage of earphones' paring form-factor. Compared with other mobile and wearable biometric modalities, EarPrint is a low-cost, accurate, and secure authentication solution for earphone users.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Rebecca N. Monastero ◽  
Srinivas Pentyala

Cytokines, including interleukins, interferons, tumor necrosis factors, and chemokines, have a variety of pro- and anti-inflammatory effects in the body through a number of biochemical pathways and interactions. Stimuli, actions, interactions, and downstream effects of cytokines have been investigated in more depth in recent years, and clinical research has also been conducted to implicate cytokines in causal patterns in certain diseases. However, particular cutoffs of cytokines as biomarkers for disease processes have not been well studied, and this warrants future work to potentially improve diagnoses for diseases with inflammatory markers. A limited number of studies in this area are reviewed, considering diseases correlated with abnormal cytokine profiles, as well as specific cutoffs at which cytokines have been deemed clinically useful for diagnosing those diseases through Receiver Operator Characteristics modeling. In light of studies such as those discussed in this review, cytokine testing has the potential to support diagnosis due to its lack of invasiveness and low cost, compared to other common types of testing for infections and inflammatory diseases.


Author(s):  
Paloma Hohmann Poier ◽  
Francisco Godke ◽  
José Aguiomar Foggiatto ◽  
Leandra Ulbricht

Abstract OBJECTIVE Develop and evaluate a low-cost walker with trunk support for senior citizens. METHOD Two-stage descriptive study: development of a walker with trunk support and evaluation with fourth age senior citizens. RESULTS Twenty-three fourth age senior citizens were selected. The evaluated criteria were the immediate influence of the walker on the static stabilometry with baropodometer and the evaluation of gait with accelerometers monitoring time and amplitude of the hip movement. There was a significant decrease in the body oscillation of senior citizens with the use of the developed walker, and there were changes in the joint amplitudes of the hip, but they were not significant. CONCLUSION Using low-cost materials, it was possible to develop and equipment that met resistance and effectiveness requirements. The walker interfered in the balance of the senior citizens, reducing significantly the static body oscillation.


Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 733-743 ◽  
Author(s):  
Conghui Liang ◽  
Hao Gu ◽  
Marco Ceccarelli ◽  
Giuseppe Carbone

SUMMARYA mechanical design and dynamics walking simulation of a novel tripod walking robot are presented in this paper. The tripod walking robot consists of three 1-degree-of-freedom (DOF) Chebyshev–Pantograph leg mechanisms with linkage architecture. A balancing mechanism is mounted on the body of the tripod walking robot to adjust its center of gravity (COG) during walking for balancing purpose. A statically stable tripod walking gait is performed by synchronizing the motions of the three leg mechanisms and the balancing mechanism. A three-dimensional model has been elaborated in SolidWorks® engineering software environment for a characterization of a feasible mechanical design. Dynamics simulation has been carried out in the MSC.ADAMS® environment with the aim to characterize and to evaluate the dynamic walking performances of the proposed design with low-cost easy-operation features. Simulation results show that the proposed tripod walking robot with proper input torques, gives limited reaction forces at the linkage joints, and a practical feasible walking ability on a flatten ground.


Author(s):  
Zulkarnay Zakaria ◽  
Mohd Fahajumi Jumaah ◽  
Mohd Saiful Badri Mansor ◽  
Khairi Mat Daud ◽  
Mohd Hafiz Fazalul Rahiman ◽  
...  

Terapi merupakan antara teknik perubatan tertua dalam mengekalkan kesihatan badan terutama daripada aliran darah yang tidak baik, strok dan beberapa penyakit yang lain. Teknik ini termasuklah akupuntur, guasa dan juga urutan. Terdapat juga teknik terapi moden seperti terapi warna, terapi ozon, terapi dadah dan banyak lagi. Kertas kajian ini akan mengetengahkan penjana terapi elektromagnet, satu alat yang mempunyai potensi aplikasi terapi dalam bidang perubatan. Alat ini menghasilkan medan magnet berfrekuensi sederhana sebagai sumber terapi. Perkakasan yang berskala kecil berfrekuensi sederhana dan berkos rendah ini telah dibangunkan dan telah diuji pada tisu biologi bagi mengukur tahap ketembusan medan magnet. Ujian ini telah membuktikan bahawa medan magnet yang telah dihasilkan mampu menembusi tisu lembut bersaiz sehingga 2 cm dengan jarak 7 cm daripada sumber. Kebolehan penembusan sistem ini terhadap tisu lembut memberikan peluang yang cerah kepada kajian ini memandangkan medan magnet telah menunjukkan potensi sebagai sebahagian daripada terapi untuk memulihkan migraine, strok, kekejangan dan beberapa yang lain selain boleh diaplikasikan dalam pengimejan tomografi induksi magnet. Kata kunci: Terapi elektromagnet, medan magnet, penembusan, tisu lembut, aplikasi perubatan Therapy is among the oldest medication technique in maintaining the health of the body especially from bad blood circulation, stroke and several others. This technique includes acupuncture, guasa and also massage. There are also modern therapy techniques like colour therapy, water therapy, ozone therapy, drug therapy and others. This paper will highlight electromagnetic therapy generator, a device which has the potential of therapy application in medical field. This device produce medium frequency magnetic field as a therapy source. This small scale medium frequency and low cost hardware that has been developed was tested on the biological tissue for the purpose of measuring the magnetic field penetration. The testing has proven that the generated magnetic field is able to penetrate the soft tissue up to 2 cm with distance from the source up to 7 cm. The capability of the system penetrations through the soft tissues provide the bright future of this research since magnetic field have shown the potential as being part of the therapy for curing migraine, stroke, cramp and several others besides the application in the magnetic induction tomography imaging. Key words: Electromagnetic therapy, magnetic field, penetration, soft tissue; medical applications


2018 ◽  
Vol 39 (4) ◽  
pp. 1565
Author(s):  
Fernanda Lúcia Passos Fukahori ◽  
Daniela Maria Bastos de Souza ◽  
Eduardo Alberto Tudury ◽  
George Chaves Jimenez ◽  
José Ferreira da Silva Neto ◽  
...  

Joint diseases are relatively common in domestic animals, such as dogs. The involved inflammation produces thermal emission, which can be imaged using specific sensors that allow capturing of infrared images. Given that there have been few reports on the use of thermography in the diagnosis of inflammation associated with diseases of the hip joint in dogs, we here propose a method for identification of inflammatory foci in dogs by using infrared thermometry. The present study aimed to find non-invasive and low-cost resources that couldfacilitate a clinical diagnosis in cases withinflammation in the coxofemoral joint of dogs.To this end, we developed a system in whichthe Flir Systems TG165 thermograph is coupled to a black PVC cannula with a 30-cm focus-to-animal distance.External effects of the environment on the temperature of the animalswere compared with the body temperature as measured by a conventional thermometer.Thirty-one dogs with and without inflammation in the coxofemoral joint underwent clinical evaluation.We verified that the temperature registered by the thermograph inthe animals with joint inflammation was significantlydifferentfrom that incontrol animals without inflammation, in the lateral projection.The method showed a sensitivity of 80%, specificity of 87.5%, and accuracy of 83.87%. This standardized method of diagnosis of inflammatory foci in the coxofemoral articulation of dogs by way of thermography showed sensitivity, specificity, and satisfactory accuracy.


2015 ◽  
Vol 1095 ◽  
pp. 620-625
Author(s):  
Jing Wei Liu ◽  
Fu Xue Zhang

The method ofinduction cladding was adopted to make nickel-base layer on the surface ofsteel components in this test, and microstructure morphology, rigiditydistribution of the alloy layer made by cladding were analyzed and studied. Theresults shows that there is obvious bright white transition zone between thecladding alloy layer and the body, which forms an excellent metallurgicalbonding, microstructure of the alloy cladding layer is eutectic structure ofaustenite + carbide (austenite dendrite can be seen at individual parts), axialand radial rigidity are evenly distributed; bonding strength of cladding alloylayer is high without air hole and slag inclusion, with high flatness ofcylindrical surface, small machining allowance and low cost, etc.


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