bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment outcome of thyroidectomies performed under local anesthesia for nodular goiter patients attending at Banadir Hospital in Mogadishu Somalia
Authors: Olow Mohamed Abdi Shire , Sönmez Recep Erçin , Hassan Mohamed Yusuf , Fıqı Abdurrahman Osman , Alimoğlu Orhan
Published: February 2020

Background: Thyroidectomy; which involves the removal of total or part of the thyroid glandis a routinely performed surgery that may have perioperative risks and complications which can be life-threatening. Objective: Main objective of this study is to determine the incidence of postthyroidectomy complications at Banadir Hospital, and to put forward the clinical benefits of those which had been performed under local anesthesia.Materials and Methods: Present study; which is prospective in nature, was conducted on 25 patients between 18 and 70 years of age who were scheduled to undergo elective thyroidectomy beginning from May to July, 2017. Blood samples for calcium, albumin, thyroid hormone levels were collected pre-operatively; within 48 hours and 5 days post-operatively. Relevant data had been achieved from the medical achieve of the department.Results: Patients between 20 and 40 years of age occupied the highest percentage of population in the study. Two (8%) patients had records of previous thyroid surgery. Ultrasonographic (USG) evaluations revealed benign thyroid nodule for 23 (92%) patients, as 2 (8%) other patients were confirmed as malignancy on their fine needle aspiration cytology (FNAC) which had suspicious findings on ultrasonographic (USG) evaluations. 21 (84%) patients had pain as the chief complaint. 19(76%) patient operations had been performed under local anesthesia, while 6(24%) patients had undergone operations undergeneral anesthesia. Total thyroidectomy was performed for 10 (40%) patients, whereas the rest (n=15 (60%) were performed with subtotal, near total and partial (lobectomy, nodulectomy) resections. No permanent hypocalcemia was recorded during the postoperative period, though 2 (8%) patients had transient hoarseness due to laryngeal nerve injury and another 2 (8%) patients had findings of surgical site infections.Conclusion: Thyroidectomy procedure could end up with undesired outcomes like nerve paralysis or hypocalcemia even at most experienced hands. Considering that, definite and precise operation should be performed at once to prevent re-operations that could increase the rate of morbidity.International Journal of Human and Health Sciences Vol. 04 No. 03 July’20 Page : 222-225
Extensive Neck Haematoma as an Extremely Rare Presentation of Thyroid Carcinoma: A Case Report
Authors: Hui Lo Ren , Ibrahim Fairuz Mohd , Abdullah Khairudin , Ahmad Nasriah , Hassan Fazilah , Mohamad Irfan
Published: February 2020

Anaplastic thyroid carcinoma (ATC) is uncommon but deadly. It is typically presented with fast growing neck mass, hoarseness or dysphagia. We report an extremely rare presentation of ATC in an elderly lady, with expanding ecchymosis involving laryngopharynx, neck and upper chest region, which causing upper airway obstruction. The rarity of presentation and the management dilemma were discussed.International Journal of Human and Health Sciences Vol. 04 No. 03 July’20 Page : 226-228
Weight Changes and Body Image in Pregnant Women: A Challenge for Health Care Professionals
Authors: Plante Anne-Sophie , Doyon Andrée-Anne , Savard Claudia ,   Groupe ÉquiLibre, Meilleur Dominique , Achim Julie , Provencher Véronique , Morisset Anne-Sophie
Published: February 2020

Body changes concerns and body image dissatisfaction are common during pregnancy. We aimed to examine whether health care professionals (HCPs): (i) believe that women are concerned about body image during pregnancy; (ii) consider it important to question, support, and intervene when pregnant women express body image concerns; (iii) feel comfortable enough in their abilities to question pregnant women with concerns; and (iv) have sufficient knowledge and skills to provide adequate support. A 36-item e-survey, developed by ÉquiLibre in collaboration with an expert committee, was sent to HCPs via email. HCPs believe that some situations are associated with body image concerns: postpregnancy weight loss (74.0%), perceived changes in their appearance (65.9%), excessive weight gain (65.3%), and feeling less in control of their body (36.8%). Among 321 responders, 60% considered it important to question pregnant women’s concerns. One in four (25.4%) considered themselves “totally comfortable” asking about weight and body image concerns. Our study showed that HCPs need to be better supported in developing their abilities to help weight-preoccupied pregnant women. There is an urgent need to clarify HCPs’ roles and to delineate the referral process as well as to ensure staff availability, in terms of time and personnel.
Existe-t-il une autonomie financière du ministrepour administrer son cabinet ?
Authors: Dussart Vincent
Published: February 2020

Il n’existe pas d’autonomie financière du ministre pour l’administration de son cabinet. En effet, cette notion concerne essentiellement des institutions dotées de la personnalité morale. Le pouvoir autonome ayant des conséquences financières tient surtout à la gestion des personnels.
KEPRIBADIAN TOKOH UTAMA DALAM NOVEL RINDU KARYA TERE LIYE: SEBUAH KAJIAN PSIKOLOGI SASTRA
Authors: Juidah Imas
Published: February 2020

Penelitian ini bertujuan untuk mendeskripsikan: (1) perjuangan menuju superior yang dilakukan tokoh utama novel Rindu karya Tere Liye, (2) pengamatan subjektif terhadap tokoh utama novel Rindu karya Tere Liye, (3) kesatuan kepribadian tokoh utama novel Rindu karya Tere Liye, (4) minat sosial tokoh utama novel Rindu karya Tere Liye, (5) gaya hidup tokoh utama novel Rindu karya Tere Liye, dan (6) kekuatan kreatif tokoh utama novel Rindu karya Tere Liye. Penelitian ini merupakan penelitian deskriptif kualitatif. Data dalam penelitian ini adalah kata-kata, kalimat, dan kutipan yang terdapat dalam novel Rindu. Sedangkan, sumber data dalam penelitian ini adalah novel Rindu karya Tere Liye yang diterbitkan oleh Republika Penerbit pada tahun 2014 sebanyak 544 lembar. Teknik pengumpulan data dalam penelitian ini adalah teknik baca dan catat. Hasil penelitian menunjukkan bahwa terdapat enam teori kepribadian pada tokoh utama yaitu tokoh Ahmad Karaeng atau Gurutta. Pertama, Perjuangan menjadi superior (striving for superiority) yang terdapat pada tokoh Gurutta dalam novel Rindu karya Tere Liye, meliputi perjuangan Gurutta dalam menggapai cita-citanya dengan memanfaatkan masa mudanya untuk belajar agama di Aceh dan Yaman. Kedua, pengamatan subjektif (subjective perceptions) yang terdapat pada tokoh Gurutta dalam novel Rindu karya Tere Liye adalah Gurutta selalu dapat menasihati dan memberikan motivasi kepada orang lain. Menurut pengamatan orang-orang di sekelilingnya, Gurutta adalah seorang ulama yang terkenal di Makassar, beradab, berilmu, dihormati, dan dicintai banyak orang karena tinggi budinya. Ketiga, kesatuan kepribadian (unity of personality) yang terdapat pada tokoh Gurutta dalam novel Rindu karya Tere Liye adalah Gurutta memiliki kepribadian yang baik hati kepada sesama, sangat tenang, penyabar, berilmu, beradab, sikapnya terbuka kepada siapapun dan dicintai dan dihormati banyak orang karena tinggi budinya. Keempat, minat sosial (social interest) yang terdapat pada tokoh Gurutta dalam novel Rindu karya Tere Liye adalah Gurutta memiliki rasa peduli kepada sesama, mau membaur dengan orang-orang yang jauh kapasitas keilmuannya dan mudah akrab dengan orang lain. Kelima, gaya hidup (style of life) yang terdapat pada tokoh Gurutta dalam novel Rindu karya Tere Liye yaitu Gurutta sangat sederhana. Dan keenam, kekuatan kreatif self (creatife power of the self) yang terdapat pada tokoh Gurutta dalam novel Rindu karya Tere Liye, Gurutta selalu memiliki ide-ide cemerlang dalam setiap permasalahan yang dihadapinya.

 

 

Kata kunci: Kepribadian, Psikologi Alfred Adler, Novel Rindu
HYDRAZIDE OF o-HYDROXYBENZOIC ACID AND ITS DERIVATIVES. SYNTHESIS AND PROPERTIES
Authors: О. А. Nurkenov  , S. D. Fazylov  , M. Zh. Zhurinov  , Zh. B. Satpaeva  , М. Zh. Burkeev  , T. M. Seilkhanov  , E. D. Satybaldin
Published: February 2020

The article presents the results of a study by the authors of the article on the development of new ways of synthesis and study of the biological activity of hydrazide derivatives of o-hydroxybenzoic acid. Methods for the preparation of hydrazone, oxadiazole, thiosemicarbazide, 1,2,4-triazole-3-thionic derivatives and methods for their further modification are described. The condensation reaction of hydroxybenzoic acid hydrazides with 1-deoxy-2,3,4,6-tetra-O-acetyl-D-glucopyranosyl isothiocyanate synthesized their corresponding acetylated glycosyl-contai-ning thiosemicarbazide derivatives. The structures of the synthesized compounds were studied by 1H and 13C NMR spectroscopy, as well as by the data of two-dimensional spectra of COSY (1H-1H) and HMQC (1H-13C). The values of chemical shifts, multiplicity, and integrated intensity of 1H and 13C signals in one-dimensional NMR spectra were determined. Using spectra in the formats COSY (1Н-1Н) and HMQC (1Н-13С), homo- and heteronuclear interactions were established, confirming the structure of the compounds under study. The results of evaluating their antimicrobial, anti-inflammatory and cytotoxic activity (in vitro) on cultures of human monocytic cell lines MonoMac-6 and THP-1Blue are described.
WEIGHT CVT TERHADAP AKSELERASI DAN DAYA SEPEDA MOTOR 115 CC
Authors: Suhaeri Suhaeri
Published: February 2020

Abstrak:  Terdapat dua sistem transmisi yang umum digunakan, yaitu transmisi manual dan transmisi otomatis atau CVT (Continuous Variable Transmission). CVT ini membutuhkan rpm yang lebih tinggi agar kopling dan automatic ratio transmitionnya berfungsi dengan baik. Sepeda motor transmisi otomatis baru bisa berjalan saat putaran mesin mencapai putaran 2400 rpm, sedangkan sepeda motor konvensional sudah bisa berjalan di atas putaran 1500 rpm [16]. Sistem CVT terdapat beberapa komponen, salah satunya adalah Primary Sheave Weight/roller. Pada eksperimen ini memodifikasi Primary Sheave Weight/roller round roller menjadi sliding roller. Tujuan dari penelitian adalah untuk mengetahui hasil daya dan torsi . Berdasarkan hasil penelitian bahwa Penggunaan Primary Sheave Weight/roller CVT (Continuous Variable Transmission)  sliding dengan ukuran berat 9,5 gram (lebih ringan dari standar) mampu menghasilkan puncak daya maksimal pada putaran mesin lebih awal yaitu 7450 rpm, sebesar 4,45 Hp, sehingga mampu menghasikan putaran bawah/akselerasi dengan daya yang lebih bertenaga, akselerasi yang baik sangat cocok digunakan pada lintasan yang banyak tikungan, rintangan, serta tidak terlalu banyak lintasan panjang dan lurus seperti lalu lintas perkotaan yang padat, karena pada lintasan ini kendaraan akan ’’ stop & go ’’. Penggunaan Primary Sheave Weight/roller CVT (Continuous Variable Transmission)  sliding dengan ukuran berat 11,5 gram (lebih berat dari standar) menghasilkan daya maksimal sebesar 4,54 Hp, pada putaran mesin lebih besar daripada Primary Sheave Weight/roller dengan berat 9,5 gram, yaitu 7800 rpm, sehingga menghasilkan putaran atas/top speed yang lebih baik, ini sangat cocok di gunakan pada lintasan yang panjang. Kata kunci : Sepeda motor 115 cc, CVT (Continuous Variable Transmission), Primary Sheave Weight/roller.
ANALISIS KELAYAKAN EKONOMI PROYEK PEMBANGUNAN GEDUNG OLAHRAGA (GOR) KABUPATEN BANGKA
Authors: Susanti Junita Eka , Maini Miskar
Published: February 2020

Dalam kegiatan pekerjaan konstruksi, analisa kelayakan pembangunan dipergunakan sebagai bahan acuan bagi pelaksana pembangunan dan menjadi standar layak atau tidaknya pembangunan suatu infrastruktur di suatu wilayah, terutama pembangunan fasilitas umum seperti pembangunan Gedung Olahraga (GOR) untuk kepentingan olahraga di suatu wilayah ataupun negara. Kemajuan prestasi olahraga suatu bangsa juga dapat mengangkat kehomatan dan nama bangsa itu sendiri. Penambahan fasilitas olahraga pada daerah atau wilayah tertentu yang kurang atau belum tersedia fasilitas olahraga merupakan tanggung jawab bersama baik pemerintah maupun swasta. Hal ini dikarenakan, GOR merupakan salah satu fasilitas publik yang perlu disediakan pemerintah dalam rangka untuk menunjang kegiatan olahraga.

Penelitian ini bertujuan untuk menganalisis investasi proyek pembangunan gedung olah raga (GOR). Adapun alat analisis yang digunakan dalam penelitian ini adalah dengan menggunakan Studi Kelayakan Aspek Keuangan yaitu dengan metode Net Present Value (NPV) Internal Rate of Return (IRR), Payback Period (PP).

Berdasarkan hasil analisis menunjukan nilai Payback Periode (PP) sebesar 12 tahun 3 bulan lebih kecil dari nilai ekonomis (20) tahun kemudian Nilai Net Present Value (NPV) pada Discount Factor 7% sebesar Rp. 30.433.056. Baik secara PP maupun NPV dan IRR Pembangunan Gedung Olahraga Tipe B Kabupaten Bangka dikatakan layak apabila nilai NPV positif, pada Discount Factor 7% positif yang pembangunan GOR layak dijalankan.
PECULIARITIES OF EVALUATION OF METHODS OF DETERMINATION OF CHARACTERISTICS OF FIRE RESISTANCE OF BUILDING STRUCTURES
Authors: Novak S , Novak M , Bedratiuk O
Published: February 2020

The results of the study aimed at further improvement and development of procedures for evaluating methods of determining the fire resistance characteristics of building structures are presented. The features of estimation of methods of determination of characteristics of fire resistance of building structures are determined. It is established that for the validation of experimental-calculation methods intended to determine the thickness of fire protection of building structures, which ensures their fire resistance in a wide range of parameters of these structures, it is impossible to use samples of structures with certain properties due to their inability to create. A procedure for such validation using a computational experiment method is proposed. In this procedure, accurate (conditional) temperature data for steel column specimens are determined by solving a direct one-dimensional non-stationary thermal conductivity problem. The validity of the proposed validation procedure by its application for the experimental calculation method, designed to determine the thickness of fire protection materials for load-bearing steel structures (columns and beams), has been established. It is established that the overwhelming number of calculated values of the thickness of the fire protection materials, determined by this method, exceeds its true values, which indicates the acceptability of the obtained results in terms of providing fire resistance of load-bearing steel structures. It is established that the difference between the calculated and actual values of the thickness of the fire protection materials can reach a considerable value (twice or more).The direction of further researches which are focused on revealing of influence of thermophysical properties of fire protection materials and stress-deformed state of samples of steel structures during the test on the accuracy of the method. This will identify more appropriate procedures for evaluating the method and processing the experimental data with increased accuracy.
Pre-Roman and Roman Period flat scrapers made of bone in the territory of Poland
Authors: Michalczewski Krzysztof , Bulas Jan
Published: February 2020

Bone tools are among the least studied artefacts, not only in the Przeworsk culture but in other regions of European Barbaricum as well. In the article, the focus is on one type of bone tool, flat scrapers, which have not as yet been sufficiently analysed. The first conclusion is that this category of finds is more widespread than previously assumed and has often been misinterpreted. One of the most interesting findings presented in the text concerns the function of those tools. Their function is reconstructed here based on the analysis of unpublished specimens recently discovered in Przeworsk culture settlements in the basins of the Nida and Nidzica Rivers, and on analysis of the published materials. Microscopic analysis of micro-traces was conducted in order to examine the proposed hypotheses. As a result, an interpretation of the spread, function, and chronology of scrapers made of bone is proposed.
A newly discovered Przeworsk culture settlement and burial ground
from the Late Pre-Roman and Roman period at Bejsce, Dist. Kazimierza Wielka – preliminary results of field-walking survey and rescue excavation
Authors: Kasiński Michał , Bulas Jan , Okońska Magdalena
Published: February 2020

The article presents preliminary results of surface survey conducted under the leadership of the authors of this paper in spring of 2019 on multicultural complex of sites occupying a hill located in south-western part of Bejsce, Dist. Kazimierza Wielka. Among discovered finds the most numerous were the pottery fragments attributed to the Przeworsk culture dated to the Late Pre-Roman period, Roman period and early phase of Migration period. Settlement or possibly complex of settlements of the Przeworsk culture covered the southern part of the surveyed terrain form, while approximately 300 m to the north from the boundary of the settlement, remains of a badly damaged necropolis, dated to Late Pre-Roman and Early Roman Period were found. Because in case of one grave, situated immediately by a deep balk, ploughing uncovered a part of its fill in situ, to prevent the ongoing destruction of the grave, a decision was made to perform rescue excavations in this place.
Effectiveness of Physiotherapy While Observing Yourself in a Mirror for Balance and Walking Speed in People Who Underwent Transtibial Amputation
Authors: Šakalienė Rasa , Urbaitė Lina
Published: February 2020

Humans face a variety of difficulties in activities of daily living and mobility after leg amputation. It affects not only their psychoemotional state but also all the locomotor apparatus. Rehabilitation focuses on gait and balance training, as this has important implications for the further development of human independence level. We attempted to ascertain whether the mirrors as the means of feedback during physiotherapy have an effect for the recovery of balance and walking speed after transtibial amputation. The aim of research was to assess the effectiveness of physiotherapy while observing oneself in a mirror for balance and walking speed after transtibial amputation. The study included 22 patients who underwent transtibial amputation 1.5–2 months ago. The study was carried out in "Orthopedijos technika" in February 2009–January 2010. The subjects were randomly divided into two groups of 11 persons. One group took conventional physiotherapy program, other – physiotherapy while observing themselves in a mirror. At baseline and at the end (after three weeks) the subjects’ walking speed and balance were assessed using "Up and go" test, "10 meter-walk" test and Berg test. Results of balance significantly improved and walking speed significantly increased in both groups after physiotherapy (p < 0.05). Physiotherapy while observing yourself in a mirror increased walking speed in persons who underwent transtibial amputation more than conventional physiotherapy but there was no significant impact on balance between these two groups.Keywords: transtibial amputation, balance, walking speed, mirror therapy.
Матеріальні наслідки фізичного насильства: кримінологічний аналіз
Authors: Медицький І. Б.
Published: February 2020

У статті обґрунтовується необхідність активізації кримінологічного пізнання фундаментальної проблеми наслідків злочинності, обсяг знань про які сприятиме створенню системи кримінологічної безпеки. Здійснено аналіз стану кримінального насильства в Україні, наведено динаміку злочинів, пов’язаних із протиправним позбавленням життя людини та заподіянням тілесних ушкоджень. На підставі макроекономічних показників розвитку, статистичних даних, систематизації та узагальнення вироків у справах про злочини проти життя та здоров’я, здійснено розрахунок економічних втрат для суспільства у зв’язку із передчасною смертю особи, а також витрат на стаціонарне лікування потерпілих від злочинів осіб.
Реформа місцевого самоврядування Йосифа II на українських землях у складі Австрійської імперії в другій половині XVIII століття
Authors: Бутирін Є. О.
Published: February 2020

У статті здійснено історико-правовий аналіз реформи місцевого самоврядування на українських землях (Галичини, Буковини, Закарпаття), які увійшли до складу Австрійської імперії у другій половині XVIII ст. Виділено, що міська ординація 1783 р. зберегла й упорядкувала самоврядування в містах, проте досконально змінила природу цього інституту, перевівши його з приватного права, яким було приватне магдебурзьке право, у сферу публічного права. Зроблені висновки про те, що модернізаційні реформи Габсбургів були спрямовані на ліквідацію відставання імперії від Пруссії. Необхідно доповнити, що без уваги імператора не залишилися й проблеми остаточної інтеграції приєднаних земель до тіла імперії.
Адміністративно-правова сутність публічної політики в контексті формування єдиного медичного простору України
Authors: Сіделковський О. Л.
Published: February 2020

У статті розглядається адміністративно-правова сутність публічної політики в контексті формування єдиного медичного простору України. Акцентовано увагу на питаннях розвитку медичного права як комплексного правового утворення. Зазначено, що метою формування єдиного медичного простору є належне забезпечення та захист прав пацієнтів при наданні їм медичної допомоги. Зроблено висновок, що ідеологія сучасної медичної реформи, відповідно до якої «гроші ходять за пацієнтом», має дотичність до адміністративно-правових засад формування єдиного медичного простору.
Застосування форм державного фінансового контролю при розслідуванні злочинів, пов'язаних із незаконним використанням бюджетних коштів у галузі охорони здоров'я
Authors: Бідняк В. А.
Published: February 2020

У науковій статті досліджено форми державного фінансового контролю, що застосовуються при розслідуванні злочинів, пов'язаних із незаконним використанням бюджетних коштів у галузі охорони здоров'я. Окрім традиційного інспектування (ревізій), акцентовано увагу на доцільності застосування фінансового аудиту, перевірки закупівель, моніторингу закупівлі. Наведено приклади їх застосування в досудовому слідстві. Проаналізовано нормативно-правові акти та думки провідних науковців із приводу проблемних питань призначення ревізій судом за ініціативою слідчого, прокурора. Надано пропозиції щодо можливих шляхів вирішення зазначеної колізії.
Product Distribution and Characteristics of Pyrolyzing Microalgae (Nannochloropsis oculata), Cotton Gin Trash, and Cattle Manure as a Cobiomass
Authors: Hanif Muhammad U. , Zwawi Mohammed , Capareda Sergio C. , Iqbal Hamid , Algarni Mohammed , Felemban Bassem F. , Bahadar Ali , Waqas Adeel
Published: February 2020

Microalgae has proven potential for producing products that are accepted as an alternate energy source. An attempt is made to further improve the efficiency of pyrolysis in terms of product yields and characteristics by adding cotton gin trash and cattle manure as a mixed feedstock (cobiomass). A statistically significant number of treatments were made by mixing different amounts of cotton gin trash and cattle manure with microalgae (Nannochloropsis oculata). These treatments were pyrolyzed at different temperatures (400 to 600 °C ) and product yields and characteristics were analyzed. The pyrolysis of cobiomass resulted in higher yield for bio-oil and char as compared to microalgae alone. An operating temperature of 500 °C was found to be the best suitable for high bio-oil yield. The high heating values (hhv) of bio-oil were observed to be maximum at 500 °C and for syngas and char, the heating value slightly increased with further increase in temperature. Comparatively, the bio-oil (30 MJ/kg) had higher heating values than char (17 MJ/kg) and syngas (13 MJ/kg). The combustible material decreased whereas fixed carbon and ash content increased in char with an increase in temperature. The bio-oil produced from cobiomass had abundant aliphatics and aromatics with low nitrogen content making it a better alternative fuel than bio-oil produced by microalgae alone. The mixing of different biomass helped improving not just the quantity but also the quality of products.
Earth-Cooling Air Tunnels for Thermal Power Plants: Initial Design by CFD Modelling
Authors: de la Rocha Camba Eduardo , Petrakopoulou Fontina
Published: February 2020

Climate change and the increase of the consumption of energy resources are expected to further strain anticipated water stress scenarios. The operation of existing thermal plants depends greatly on their cooling capacity, for which large amounts of water are withdrawn and consumed. Dry-cooling systems, on the other hand, do not require water, but they are less efficient and more expensive relative to conventional water-based systems, because of their dependency on the ambient temperature. This paper introduces the new idea of replacing water-based cooling systems in thermal power plants with earth-cooling air tunnels. Based on the concept of existing earth-air heat exchangers, the system takes advantage of the low and relatively constant underground temperature for cooling ambient air before it is introduced in the air condenser of the plant. In this work, we present an initial design of such an open-loop system for a 20 MW concentrated solar power plant. A sensitivity study of both geometric and flow parameters is realized using computational fluid dynamics simulations. Under the requirements of the study, we find that a system using a design of pipes with 0.5 m diameter and about 300 m length can be considered a technically viable zero-water alternative to water-cooling technologies.
A Solution of Implicit Model of Series-Parallel Photovoltaic Arrays by Using Deterministic and Metaheuristic Global Optimization Algorithms
Authors: Pérez Archila Luis Miguel , Bastidas-Rodríguez Juan David , Correa Rodrigo , Trejos Grisales Luz Adriana , Gonzalez-Montoya Daniel
Published: February 2020

The implicit model of photovoltaic (PV) arrays in series-parallel (SP) configuration does not require the LambertW function, since it uses the single-diode model, to represent each submodule, and the implicit current-voltage relationship to construct systems of nonlinear equations that describe the electrical behavior of a PV generator. However, the implicit model does not analyze different solution methods to reduce computation time. This paper formulates the solution of the implicit model of SP arrays as an optimization problem with restrictions for all the variables, i.e., submodules voltages, blocking diode voltage, and strings currents. Such an optimization problem is solved by using two deterministic (Trust-Region Dogleg and Levenberg Marquard) and two metaheuristics (Weighted Differential Evolution and Symbiotic Organism Search) optimization algorithms to reproduce the current–voltage (I–V) curves of small, medium, and large generators operating under homogeneous and non-homogeneous conditions. The performance of all optimization algorithms is evaluated with simulations and experiments. Simulation results indicate that both deterministic optimization algorithms correctly reproduce I–V curves in all the cases; nevertheless, the two metaheuristic optimization methods only reproduce the I–V curves for small generators, but not for medium and large generators. Finally, experimental results confirm the simulation results for small arrays and validate the reference model used in the simulations.
Study of the Antioxidant Power of the Waste Oil from Palm Oil Bleaching Clay
Authors: Cunha de Melo Katiane , Silva de Oliveira Ingrid , Helena de Oliveira Pires Luiza , Santos do Nascimento Luís Adriano , Roberto Zamian José , Narciso da Rocha Filho Geraldo , Fonseca Passos Marcele , Santos Lopes Alessandra , Converti Attilio , Costa Carlos Emmerson Ferreira da
Published: February 2020

Palm oil is one of the most consumed oils, one of whose refining steps is the removal of pigments and other substances using bleaching clay as adsorbent. Worldwide production of this oil was 70 million tons in 2017, requiring 1 t of clay to produce 1000 t of refined oil. The residual bleaching clay, having an oil fraction (12.70%) rich in phenolics, carotenoids and tocopherols, was extracted in this study with ethanol to obtain an antioxidant-rich palm oil bleaching extract (POBE), with the aim of using it as a natural antioxidant source. The POBE antioxidant capacity determined by the DPPH method corresponded to a 20.29% inhibition of radical formation. The POBE was also tested for its potential to enhance oxidative stability of passion fruit, pracaxi and Brazil nut oils used as reference oils, and compared to common synthetic antioxidants (tert-butylhydroquinone and propyl gallate), either separately as controls or in mixtures with them. Besides the increased oxidative stability of these oils induced by the POBE, a positive synergistic effect between it and the synthetic antioxidants was observed. These results taken together suggest that the exploitation of the waste oil from bleaching clay as an additive to improve the oxidative stability of biofuels or lubricating oils is feasible.
Development of an Improved LMD Method for the Low-Frequency Elements Extraction from Turbine Noise Background
Authors: Liao Lida , Huang Bin , Tan Qi , Huang Kan , Ma Mei , Zhang Kang
Published: February 2020

Given the prejudicial environmental effects of fossil-fuel based energy production, renewable energy sources can contribute significantly to the sustainability of human society. As a clean, cost effective and inexhaustible renewable energy source, wind energy harvesting has found a wide application to replace conventional energy productions. However, concerns have been raised over the noise generated by turbine operating, which is helpful in fault diagnose but primarily identified for its adverse effects on the local ecosystems. Therefore, noise monitoring and separation is essential in wind turbine deployment. Recent developments in condition monitoring provide a solution for turbine noise and vibration analysis. However, the major component, aerodynamic noise is often distorted in modulation, which consequently affects the condition monitoring. This study is conducted to explore a novel approach to extract low-frequency elements from the aerodynamic noise background, and to improve the efficiency of online monitoring. A framework built on the spline envelope method and improved local mean decomposition has been developed for low-frequency noise extraction, and a case study with real near-field noises generated by a mountain-located wind turbine was employed to validate the proposed approach. Results indicate successful extractions with high resolution and efficiency. Findings of this research are also expected to further support the fault diagnosis and the improvement in condition monitoring of turbine systems.
Catalytic Steam Reforming of Toluene: Understanding the Influence of the Main Reaction Parameters over a Reference Catalyst
Authors: Zhu Hua Lun , Pastor-Pérez Laura , Millan Marcos
Published: February 2020

Identifying the suitable reaction conditions is key to achieve high performance and economic efficiency in any catalytic process. In this study, the catalytic performance of a Ni/Al2O3 catalyst, a benchmark system—was investigated in steam reforming of toluene as a biomass gasification tar model compound to explore the effect of reforming temperature, steam to carbon (S/C) ratio and residence time on toluene conversion and gas products. An S/C molar ratio range from one to three and temperature range from 700 to 900 °C was selected according to thermodynamic equilibrium calculations, and gas hourly space velocity (GHSV) was varied from 30,600 to 122,400 h−1 based on previous work. The results suggest that 800 °C, GHSV 61,200 h−1 and S/C ratio 3 provide favourable operating conditions for steam reforming of toluene in order to get high toluene conversion and hydrogen productivity, achieving a toluene to gas conversion of 94% and H2 production of 13 mol/mol toluene.
Automatic Coal and Gangue Segmentation Using U-Net Based Fully Convolutional Networks
Authors: Gao Rong , Sun Zhaoyun , Li Wei , Pei Lili , Hu Yuanjiao , Xiao Liyang
Published: February 2020

Sorting gangue from raw coal is an essential concern in coal mining engineering. Prior to separation, the location and shape of the gangue should be extracted from the raw coal image. Several approaches regarding automatic detection of gangue have been proposed to date; however, none of them is satisfying. Therefore, this paper aims to conduct gangue segmentation using a U-shape fully convolutional neural network (U-Net). The proposed network is trained to segment gangue from raw coal images collected under complex environmental conditions. The probability map outputted by the network was used to obtain the location and shape information of gangue. The proposed solution was trained on a dataset consisting of 54 shortwave infrared (SWIR) raw coal images collected from Datong Coalfield. The performance of the network was tested with six never seen images, achieving an average area under the receiver operating characteristics (AUROC) value of 0.96. The resulting intersection over union (IoU) was on average equal to 0.86. The results show the potential of using deep learning methods to perform gangue segmentation under various conditions.
Analytical Methods to Estimate the Thermal Transmittance of LSF Walls: Calculation Procedures Review and Accuracy Comparison
Authors: Santos Paulo , Lemes Gabriela , Mateus Diogo
Published: February 2020

An accurate evaluation of the thermal transmittance ( U -value) of building envelope elements is fundamental for a reliable assessment of their thermal behaviour and energy efficiency. Simplified analytical methods to estimate the U -value of building elements could be very useful to designers. However, the analytical methods applied to lightweight steel framed (LSF) elements have some specific features, being more challenging to use and to obtain a reliable accurate U -value with. In this work, the main analytical methods available in the literature were identified, the calculation procedures were reviewed and their accuracy was evaluated and compared. With this goal, six analytical methods were used to estimate the U -values of 80 different LSF wall models. The obtained analytical U -values were compared with those provided by numerical simulations, which were used as reference U -values. The numerical simulations were performed using a 2D steady-state finite element method (FEM)-based software, THERM. The reliability of these numerical models was ensured by comparison with benchmark values and by an experimental validation. All the evaluated analytical methods showed a quite good accuracy performance, the worst accuracy being found in cold frame walls. The best and worst precisions were found in the Modified Zone Method and in the Gorgolewski Method 2, respectively. Very surprisingly, the ISO 6946 Combined Method showed a better average precision than other two methods, which were specifically developed for LSF elements.
A Li-Ion Battery Thermal Management System Combining a Heat Pipe and Thermoelectric Cooler
Authors: Zhang Chuanwei , Xia Zhan , Wang Bin , Gao Huaibin , Chen Shangrui , Zong Shouchao , Luo Kunxin
Published: February 2020

The temperature of electric vehicle batteries needs to be controlled through a thermal management system to ensure working performance, service life, and safety. In this paper, TAFEL-LAE895 100Ah ternary Li-ion batteries were used, and discharging experiments at different rates were conducted to study the surface temperature increasing characteristics of the battery. To dissipate heat, heat pipes with high thermal conductivity were used to accelerate dissipating heat on the surface of the battery. We found that the heat pipe was sufficient to keep the battery temperature within the desired range with a midlevel discharge rate. For further improvement, an additional thermoelectric cooler was needed for a high discharge rate. Simulations were completed with a battery management system based on a heat pipe and with a combined heat pipe and thermoelectric cooler, and the results were in line with the experimental results. The findings show that the combined system can effectively reduce the surface temperature of a battery within the full range of discharge rates expected in the battery used.
Performance Analysis of an Electromagnetically Coupled Piezoelectric Energy Scavenger
Authors: Pasharavesh Abdolreza , Moheimani Reza , Dalir Hamid
Published: February 2020

The deliberate introduction of nonlinearities is widely used as an effective technique for the bandwidth broadening of conventional linear energy harvesting devices. This approach not only results in a more uniform behavior of the output power within a wider frequency band through bending the resonance response, but also contributes to energy harvesting from low-frequency excitations by activation of superharmonic resonances. This article investigates the nonlinear dynamics of a monostable piezoelectric harvester under a self-powered electromagnetic actuation. To this end, the governing nonlinear partial differential equations of the proposed harvester are order-reduced and solved by means of the perturbation method of multiple scales. The results indicate that, according to the excitation amplitude and load resistance, different responses can be distinguished at the primary resonance. The system behavior may involve the traditional bending of response curves, Hopf bifurcations, and instability regions. Furthermore, an order-two superharmonic resonance is observed, which is activated at lower excitations in comparison to order-three conventional resonances of the Duffing-type resonator. This secondary resonance makes it possible to extract considerable amounts of power at fractions of natural frequency, which is very beneficial in micro-electro-mechanical systems (MEMS)-based harvesters with generally high resonance frequencies. The extracted power in both primary and superharmonic resonances are analytically calculated, then verified by a numerical solution where a good agreement is observed between the results.
Design and Modeling of an Integrated Flywheel Magnetic Suspension for Kinetic Energy Storage Systems
Authors: Andriollo Mauro , Benato Roberto , Tortella Andrea
Published: February 2020

The paper presents a novel configuration of an axial hybrid magnetic bearing (AHMB) for the suspension of steel flywheels applied in power-intensive energy storage systems. The combination of a permanent magnet (PM) with excited coil enables one to reduce the power consumption, to limit the system volume, and to apply an effective control in the presence of several types of disturbances. The electromagnetic design of the AHMB parts is carried out by parametric finite element analyses with the purpose to optimize the force performances as well as the winding inductance affecting the electrical supply rating and control capability. Such investigation considers both the temperature dependence of the PM properties and the magnetic saturation effects. The electrical parameters and the force characteristics are then implemented in a control scheme, reproducing the electromechanical behavior of the AHMB-flywheel system. The parameter tuning of the controllers is executed by a Matlab/Simulink code, examining the instantaneous profiles of both the air-gap length and the winding ampere-turns. The results of different dynamic tests are presented, evidencing the smooth air-gap changes and the optimized coil utilization, which are desirable features for a safe and efficient flywheel energy storage.
Theoretical and Numerical Study of a Photovoltaic System with Active Fluid Cooling by a Fully-Coupled 3D Thermal and Electric Model
Authors: D’Angola Antonio , Enescu Diana , Mecca Marianna , Ciocia Alessandro , Leo Paolo Di , Fracastoro Giovanni Vincenzo , Spertino Filippo
Published: February 2020

The paper deals with the three-dimensional theoretical and numerical investigation of the electrical performance of a Photovoltaic System (PV) with active fluid cooling (PVFC) in order to increase its efficiency in converting solar radiation into electricity. The paper represents a refinement of a previous study by the authors in which a one-dimensional theoretical model was presented to evaluate the best compromise, in terms of fluid flow rate, of net power gain in a cooled PV system. The PV system includes 20 modules cooled by a fluid circulating on the bottom, the piping network, and the circulating pump. The fully coupled thermal and electrical model was developed in a three-dimensional geometry and the results were discussed with respect to the one-dimensional approximation and to experimental tests. Numerical simulations show that a competitive mechanism between the power gain due to the cell temperature reduction and the power consumption of the pump exists, and that a best compromise, in terms of fluid flow rate, can be found. The optimum flow rate can be automatically calculated by using a semi-analytical approach in which irradiance and ambient temperature of the site are known and the piping network losses are fully characterized.
Exploratory Research of CO2, Noise and Metabolic Energy Expenditure in Lisbon Commuting
Authors: Soares Angelo , Catita Cristina , Silva Carla
Published: February 2020

The lower cost of sensors is making possible the acquisition of big data sets in several applications and research areas. Indoor air quality and commuter exposure to pollutants are some of these areas, which can have impacts on our livelihood. The main objective of this exploratory research was to assemble portable equipment along with a prototype, one low-cost and easy to replicate in any location worldwide. We answer how CO2, noise and energy expenditure compare in different transportation modes with indoor environments (metro, bus and car). It was intended to be carried by a subject on all commutes. The low-cost equipment assembled has the ability to measure ambient CO2, noise levels, heart rate and geographic coordinates. The field campaign was conducted on an urban commuting route, in Lisbon city, between Rossio (downtown of Lisbon city) and Campo Grande (near FCUL campus). It took place during 3 weeks in school break and 3 weeks in the school period to grasp some differences between these periods of the year. The heart rate data was used to calculate the subject energy expenditure and the geographic coordinate data allowed for time and spatial analysis using a geospatial software package. Our measurements totaled 70 one-way trips and 358,140 data points. Temporal and spatial analysis yielded the following results: The metro presents the lowest median CO2 concentrations of 693 ppm and the bus the highest with 1085 ppm. The bus had an equivalent continuous sound average (Leq) of 75 dBA, while the metro had 85.2 dBA. Based on the metabolic equivalent of task (MET) calculations, the metro displays the least sedentary behavior, while the bus presents the most sedentary behavior with up to 96.5% of its commute spent in this classification. The metro was the fastest mode of transportation based on the consistency of its travel times compared to the bus, which despite also being consistent, was slower by 1.8 times. The car measurement values reside in the middle of the metro and bus results. Despite this, it is considered the worst mode of transportation, as it goes against the idea of a less congested and clean city. It also has a highly variable commuting time, which sometimes makes it slower than the metro, especially during the school period. According to our results, we concluded that the metro had efficient indoor ventilation while the bus did not. There were several instances of inefficient ventilation with concentrations exceeding 1000 ppm, particularly between Restauradores and Saldanha due to overcrowding. Referring to the health impacts of noise, the metro dBA levels are not sustained for enough time to have any measurable negative impact. Sensor performance was considered acceptable for the CO2 sensor. The dBA and heart rate (HR) sensors were considered acceptable to sometimes irregular in nature, which was expected and taken into consideration.
Recombinant Irisin Prevents the Reduction of Osteoblast Differentiation Induced by Stimulated Microgravity through Increasing β-Catenin Expression
Authors: Chen Zhihao , Zhang Yan , Zhao Fan , Yin Chong , Yang Chaofei , Wang Xue , Wu Zixiang , Liang Shujing , Li Dijie , Lin Xiao , Tian Ye , Hu Lifang , Li Yu , Qian Airong
Published: February 2020

Background: Irisin, a novel exercise-induced myokine, was shown to mediate beneficial effects of exercise in osteoporosis. Microgravity is a major threat to bone homeostasis of astronauts during long-term spaceflight, which results in decreased bone formation. Methods: The hind-limb unloading mice model and a random position machine are respectively used to simulate microgravity in vivo and in vitro. Results: We demonstrate that not only are bone formation and osteoblast differentiation decreased, but the expression of fibronectin type III domain-containing 5 (Fdnc5; irisin precursor) is also downregulated under simulated microgravity. Moreover, a lower dose of recombinant irisin (r-irisin) (1 nM) promotes osteogenic marker gene (alkaline phosphatase (Alp), collagen type 1 alpha-1(ColIα1)) expressions, ALP activity, and calcium deposition in primary osteoblasts, with no significant effect on osteoblast proliferation. Furthermore, r-irisin could recover the decrease in osteoblast differentiation induced by simulated microgravity. We also find that r-irisin increases β-catenin expression and partly neutralizes the decrease in β-catenin expression induced by simulated microgravity. In addition, β-catenin overexpression could also in part attenuate osteoblast differentiation reduction induced by simulated microgravity. Conclusions: The present study is the first to show that r-irisin positively regulates osteoblast differentiation under simulated microgravity through increasing β-catenin expression, which may reveal a novel mechanism, and it provides a prevention strategy for bone loss and muscle atrophy induced by microgravity.