bluuebunny/crossref_metadata_2025 huggingface dataset:
“Crônica de uma morte anunciada”: o colapso do sistema penitenciário brasileiro e o “paradigma do campo” como expressão da produção da “vida nua”
Authors: Wermuth Maiquel Ângelo Dezordi , Nielsson Joice Graciele
Published: May 2017

Partindo dos massacres ocorridos nas penitenciárias de Alcaçuz e no Complexo Penitenciário Anísio Jobim, em janeiro de 2017, o presente artigo busca discutir a situação carcerária no país, utilizando-se, como pano de fundo, a filosofia foucaultiana e agambeniana a fim de averiguar em que medida as penitenciárias brasileiras são representações de campos nos quais a produção da vida desqualificada e impunemente matável, é a expressão máxima da biopolítica do nosso tempo. Como hipótese provisória, tem-se que, a partir de um olhar biopolítico a pena privativa de liberdade se coloca como uma medida de incapacitação seletiva de determinados grupos, majoritariamente, homens jovens, negros e pobres. Nestes verdadeiros “depósitos humanos”, apenados se assemelham ao homo sacer, e a situação caótica revela-se como uma situação de campo, ou seja, um espaço no qual uma violência sem precedentes ceifa aquelas vidas consideradas indignas de serem vividas. O texto encontra-se estruturado em duas partes. Na primeira, analisa-se o cenário penitenciário atual, seu caráter seletivo e a constante violação de direitos humanos dos apenados, e após, procura-se evidenciar como a situação penitenciária brasileira permite a afirmação de que as instituições carcerárias do país se aproximam ao paradigma do campo revelado pela obra agambeniana. Para a concretização da pesquisa, a metodologia de abordagem utilizada foi a fenomenologia hermenêutica, a qual visa à aproximação entre o sujeito (pesquisadores) e o objeto a ser pesquisado (no caso, a situação caótica do sistema carcerário no Brasil). Com efeito, o presente artigo parte da ideia de que os sujeitos (os autores do texto) estão diretamente implicados no objeto da pesquisa, que com eles interage e sofre as consequências dos seus resultados. Por fim, conclui que o colapso do sistema penitenciário brasileiro se assemelhava a uma morte anunciada e amplamente divulgada, especialmente após o massacre do Carandiru, refletindo, portanto, o paradigma biopolítico do campo.
Demarcação da ciência e a sociologia do direito II
Authors: Da Silva Artur Stamford
Published: May 2017

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Clinical and Demographic Predictors of Acute Pulmonary Embolism in Central Africa Using 64-Rows Multi-Detector Computed Tomography Angiography
Authors: Lomamba Florent Wetshokonda , Tshibola Jean Mukaya , Tshikwela Michel Lelo
Published: May 2017

Background: Acute pulmonary embolism is a life-threatening entity. Its diagnosis remains a challenge for clinicians and it is important to be aware of factors that increase risks of the disease. In this study, we access the clinical and demographic predictors of pulmonary embolism using 64-rows multi-detector Computed Tomography Angiography in central Africa.

Methods: From 01 January to 30 July 2016, the data record of patients who underwent chest 64-rows multi-detector Computed Tomography Angiography indicated for clinical suspicion of acute pulmonary embolism at Biamba Marie Mutombo Dikembe Hospital were retrospectively were revisited and analyzed using logistic regression models.

Results: Sixty-five consecutive patients (age range, 24 to 84 years and mean age 56.8 ± 14.9 years) were included with a female predominance. Pulmonary embolism was formerly detected in 17 patients (26.2% of cases). Age ≥ 65 years (OR = 9.5 CI 95%:14.74, 60.79, p = 0.018) and obesity (OR = 40.8 CI 95%:2.85, 58.44, p = 0.006) were the predictors of pulmonary embolism. Heart disease and pneumonia were the main pathologies associated and the main alternative diagnoses.

Conclusion: This study shows that age and obesity were independent predictors of PE. In central Africa where Computed Tomography machine is not widely available, aged and obese patients with a clinical suspicion of pulmonary embolism should be dealt with as a higher suspicion of true pulmonary embolism.
A National Effort to Prevent Type 2 Diabetes: Participant-Level Evaluation of CDC’s National Diabetes Prevention Program
Authors: Ely Elizabeth K. , Gruss Stephanie M. , Luman Elizabeth T. , Gregg Edward W. , Ali Mohammed K. , Nhim Kunthea , Rolka Deborah B. , Albright Ann L.
Published: May 2017

OBJECTIVE

To assess participant-level results from the first 4 years of implementation of the National Diabetes Prevention Program (National DPP), a national effort to prevent type 2 diabetes in those at risk through structured lifestyle change programs.

RESEARCH DESIGN AND METHODS

Descriptive analysis was performed on data from 14,747 adults enrolled in year-long type 2 diabetes prevention programs during the period February 2012 through January 2016. Data on attendance, weight, and physical activity minutes were summarized and predictors of weight loss were examined using a mixed linear model. All analyses were performed using SAS 9.3.

RESULTS

Participants attended a median of 14 sessions over an average of 172 days in the program (median 134 days). Overall, 35.5% achieved the 5% weight loss goal (average weight loss 4.2%, median 3.1%). Participants reported a weekly average of 152 min of physical activity (median 128 min), with 41.8% meeting the physical activity goal of 150 min per week. For every additional session attended and every 30 min of activity reported, participants lost 0.3% of body weight (P < 0.0001).

CONCLUSIONS

During the first 4 years, the National DPP has achieved widespread implementation of the lifestyle change program to prevent type 2 diabetes, with promising early results. Greater duration and intensity of session attendance resulted in a higher percent of body weight loss overall and for subgroups. Focusing on retention may reduce disparities and improve overall program results. Further program expansion and investigation is needed to continue lowering the burden of type 2 diabetes nationally.
Efficacy of the Telemedical Lifestyle intervention Program TeLiPro in Advanced Stages of Type 2 Diabetes: A Randomized Controlled Trial
Authors: Kempf Kerstin , Altpeter Bernd , Berger Janine , Reuß Oliver , Fuchs Matthias , Schneider Michael , Gärtner Babette , Niedermeier Katja , Martin Stephan
Published: May 2017

OBJECTIVE

Lifestyle interventions are the foundation of treatment in newly diagnosed type 2 diabetes. However, their therapeutic potential in advanced disease stages is unknown. We evaluated the efficacy of the Telemedical Lifestyle intervention Program (TeLiPro) in improving metabolic control in advanced-stage type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this single-blind, active comparator, intervention study, patients with type 2 diabetes (with glycated hemoglobin [HbA1c] ≥7.5% [58.5 mmol/mol]), and BMI ≥27 kg/m2 and on ≥2 antidiabetes medications) were recruited in Germany and randomized 1:1 using an electronically generated random list and sealed envelopes into two parallel groups. The data analyst was blinded after assignment. The control group (n = 100) got weighing scales and step counters and remained in routine care. The TeLiPro group (n = 102) additionally received telemedical coaching including medical-mental motivation, a formula diet, and self-monitored blood glucose for 12 weeks. The primary end point was the estimated treatment difference in HbA1c reduction after 12 weeks. All available values per patient (n = 202) were analyzed. Analyses were also performed at 26 and 52 weeks of follow-up.

RESULTS

HbA1c reduction was significantly higher in the TeLiPro group (mean ± SD −1.1 ± 1.2% vs. −0.2 ± 0.8%; P < 0.0001). The estimated treatment difference in the fully adjusted model was 0.8% (95% CI 1.1; 0.5) (P < 0.0001). Treatment superiority of TeLiPro was maintained during follow-up (week 26: 0.6% [95% CI 1.0; 0.3], P = 0.0001; week 52: 0.6% [0.9; 0.2], P < 0.001). The same applies for secondary outcomes: weight (TeLiPro −6.2 ± 4.6 kg vs. control −1.0 ± 3.4 kg), BMI (−2.1 ± 1.5 kg/m2 vs. −0.3 ± 1.1 kg/m2), systolic blood pressure (−5.7 ± 15.3 mmHg vs. −1.6 ± 13.8 mmHg), 10-year cardiovascular disease risk, antidiabetes medication, and quality of life and eating behavior (P < 0.01 for all). The effects were maintained long-term. No adverse events were reported.

CONCLUSIONS

In advanced-stage type 2 diabetes, TeLiPro can improve glycemic control and may offer new options to avoid pharmacological intensification.
HUBUNGAN PERSONAL HYGIENE DENGAN KEBERADAAN ESCHERICHIA COLI PADA MAKANAN DI TEMPAT PENGOLAHAN MAKANAN (TPM) BUFFER AREA BANDARA ADI SOEMARMO SURAKARTA
Authors: Romanda Fitka , Priyambodo Priyambodo , Risanti Erika Diana
Published: May 2017

Keberadaan Escherichia coli dalam sumber air atau makanan merupakan indikasi pasti terjadinya  kontaminasi tinja manusia. Kontaminasi ini dapat berdampak pada Kejadian Luar Biasa keracunan makanan di negara berkembang, termasuk di Indonesia. Adanya kontaminasi Escherichia coli pada makanan dapat disebabkan faktor personal hygiene penjamah makanan yang kurang baik. Penelitian ini bertujuan untuk mengetahui adanya hubungan personal hygiene penjamah makanan dengan Escherichia coli. Penelitian ini menggunakan metode observasional dengan pendekatan cross sectional. Subyek penelitian adalah 65 penjamah makanan dan 65 sampel makanan di 22 tempat pengolahan makanan buffer area Bandara Adi Soemarmo Surakarta. Hasil penelitian menunjukan adanya hubungan personal hygiene dengan keberadaan Escherichia coli pada makanan di Tempat Pengolahan Makanan Buffer Area Bandara Adi Soemarmo Surakarta dengan uji statistik dengan Chi Square didapatkan p value (0,000) dan kekuatan hubungan sedang dengan nilai C (0,477). Berdasarkan hasil penelitian, disimpulkan terdapat hubungan personal hygiene penjamah makanan dengan keberadaan Escherichia coli pada makanan di tempat pengolahan makanan (TPM) buffer area Bandara Adi Soemarmo Surakarta. Kata kunci. Personal Hygiene, Escherichia coli, Buffer Area
PERBEDAAN KEBERADAAN JENTIK AEDES AEGYPTI ANTARA BAK MANDI DI PERDESAAN DAN PERKOTAAN DI KECAMATAN WONOGIRI
Authors: Sidiq Muhamad Nur , Iskandar Iskandar , Romadhon Yusuf Alam
Published: May 2017

Pemeriksaan jentik Aedes aegypti dilakukan dalam mengurangi angka kesakitan demam berdarah dengue. Tujuan dari penelitian ini adalah mengetahui perbedaan jumlah jentik Aedes aegypti antara bak mandi di perdesaan dan perkotaan .Penelitian ini menggunakan jenis penelitian observasional analitik dengan pendekatan cross sectional. Penelitian dilakukan di wilayah Kecamatan Wonogiri pada bulan Oktober-November 2015. Besar sampel adalah 100 responden di wilayah Kecamtan Wonogiri yang tersebar di 15 kelurahan dan desa. Uji statistik yang digunakan adalah Chi square. Hasil penelitian menunjukkan bahwa jumlah jentik Aedes aegypti di perkotaan lebih banyak daripada di perdesaan (42% vs 14%) dengan p= < 0,002. Kesimpulan: jumlah jentik Aedes aegypti di perkotaan lebih banyak daripada di perdesaan di kecamatan Wonogiri. Kata kunci. Keberadaan jentik, Aedes aegypti, Bak mandi, Perdesaan, Perkotaan
THE EFFECTIVENESS OF 70% METHANOLIC EXTRACT OF AVOCADO LEAF (Persea americana Mill) IN DECREASING BLOOD SUGAR LEVELS IN MALE RATS (Rattus norvegicus) WISTAR STRAIN INDUCED ALLOXAN
Authors: Sintowati Retno , Handayani Anindita Putri , Aisyah Riandini
Published: May 2017

Tanaman alpukat (Persea americana Mill) merupakan tanaman tradisional yang memiliki kandungan flavonoid dan tannin yang dapat menurunkan kadar gula darah. Tujuan penelitian ini adalah untuk mengetahui efektivitas ekstrak metanol 70% daun alpukat (Persea americana Mill) terhadap penurunan kadar gula darah.Metode penelitian menggunakan eksperimental laboratorik dengan rancangan penelitian pretest – posttest with control group design. Hewan uji yang digunakan 25 ekor tikus jantan galur Wistar, umur 2-3 bulan, dan berat badan 150-200 gram yang dibagi dalam 5 kelompok. Kelompok I: kontrol negatif (aquades), kelompok II: kontrol positif (glibenklamid), kelompok III, IV, V : ekstrak metanol 70% daun alpukat dengan dosis berturut-turut adalah sebagbai berikut: 100 mg/ 200 grBB, 150 mg/ 200 grBB, 200 mg/ 200 grBB. Gula darah diukur dengan alat spektrofotometer. Berdasarkan hasil uji ANOVA, data penurunan kadar gula darah hari ke-7 pemberian ekstrak nilai probabilitas signifikan p = 0, 000 dengan demikian p < 0, 05 maka terdapat perbedaan penurunan kadar gula darah yang bermakna. Berdasarkan uji LSD dari semua kelompok didapatkan nilai p < 0,05 yang berarti terdapat perbedaan penurunan kadar gula darah yang signifikan antara2 kelompok. Kesimpulan: Ekstrak metanol 70% daun alpukat (Persea americana Mill) dosis 200 mg/200; 100 mg/200 and 150 mg/ 200 gram/berat badan dapat menurunkan kadar gula darah pada mencit jantan galur wistarKata Kunci : Ekstrak metanol 70%, Alpukat (Persea americana Mill), gula darah, diabetes mellitus.
PERBEDAAN STATUS GIZI BAYI BERUMUR 4–6 BULAN PADA PEMBERIAN ASI EKSKLUSIF DENGAN ASI NON EKSKLUSIF
Authors: Dasuki Muh. Shoim , Karuniawati Mira Candra , Candrasari Anika
Published: May 2017

Cakupan pemberian ASI eksklusif di Indonesia hanya 42%. Survey tahun 2013, menemukan sekitar 19,6% balita Indonesia menderita kekurangan gizi. Tujuan penelitian ini adalah untuk mengetahui perbedaan status gizi bayi berumur 4–6 bulan yang diberikan ASI eksklusif dengan yang tidak diberikan ASI eksklusif. Penelitian ini menggunakan metode penelitian observasional analitik dengan pendekatan cross sectional. Sejumlah 80 bayi berusia 4-6 bulan diambil dengan teknik purposive sampling. Uji statistik yang digunakan adalah Chi Square. Hasil penelitian didapatkan nilai p=0,000 (p<0,05) yang artinya terdapat perbedaan signifikan antara status gizi bayi berumur 4–6 bulan yang diberikan ASI eksklusif dengan yang tidak diberikan ASI eksklusif. Diperoleh dari 40 bayi yang diberikan ASI eksklusif mempunyai status gizi lebih baik dibandingkan dengan tidak berikan ASI eksklusif. Status gizi buruk lebih banyak ditemukan pada kelompok bayi yang tidak diberikan ASI eksklusif. Terdapat perbedaan status gizi bayi berumur 4–6 bulan yang diberikan ASI eksklusif dengan yang tidak diberikan ASI eksklusif.Kata Kunci: ASI Eksklusif, ASI Non Eksklusif, status gizi
PERBEDAAN NILAI RERATA KVP % PREDIKSI DAN KV % PREDIKSI ANTARA ORANG DENGAN INDEKS MASSA TUBUH NORMAL DAN DI ATAS NORMAL
Authors: Basuki Sri Wahyu , Primasakti Irkhamyudhi , Sari Riana
Published: May 2017

Kapasitas vital paksa (KVP) dan kapasitas vital (KV) merupakan parameter dalam pemeriksaan spirometri untuk mengetahui kelainan restriksi paru. Beberapa penelitian telah melaporkan bahwa orang IMT di atas normal memiliki kelainan restriksi pada paru mereka. Penelitian ini untuk mengetahui perbedaan nilai rerata KVP % prediksi dan KV % prediksi antara orang dengan IMT normal dan di atas normal di Universitas Muhammadiyah Surakarta. Desain penelitian yang digunakan adalah metode analitik observasional dengan pendekatan cross sectional. Besar sampel 35 orang laki-laki 18-25 tahun tiap kelompoknya. Pengambilan sampel menggunakan teknik purposive sampling. Perbedaan nilai rerata KVP % prediksi dan KV % prediksi dianalisis menggunakan uji hipotesis yaitu uji t dua kelompok tidak berpasangan dan Mann-Whitney dengan program SPSS 20.0 for windows.Hasil penelitian terdapat perbedaan yang signifikan nilai rerata KVP % prediksi dan KV % prediksi pada orang dengan indeks massa tubuh normal (KVP 83,9580 % dan KV 112,8063 %) dan IMT di atas normal (KVP 70,4734% dan KV 79,7374%). Hasil hipotesis uji t dua kelompok tidak berpasangan didapatkan significancy 0,000 (p<0,05) dan Mann-Whitney didapatkan significancy 0,001 (p<0,05). Terdapat perbedaan yang signifikan nilai rerata KVP % prediksi dan KV % prediksi antara orang dengan IMT normal dan IMT di atas normal.Kata kunci: KVP % prediksi dan KV % prediksi, IMT normal dan di atas normal
Three-Dimensional Numerical Simulation of Rear Point Contact Crystalline Silicon Solar Cells
Authors: M.Zanuccoli  , H.-W. Guo  , E. Sangiorgi  , C. Fiegna
Published: May 2017

High efficiency monocrystalline solar cells commonly adopts rear point contacts of limited extension and passivation of the uncontacted bottom silicon surface region in order to improve performance. Modeling and analysis of advanced solar cells is strategic to optimize the device design and to minimize the losses. Several competing physical mechanisms must be accounted for in order to properly analyze rear point contact solar cells and a three-dimensional (3D) analysis of complex geometries is required. In this work we describe the issues related to the design of the mesh grid for the 3D numerical simulations, the definition of appropriate boundary conditions and the main adopted assumptions. Examples of numerical simulations are reported.
Nowcasting of Wind Speed using Support Vector Regression. Experiments with Time Series from Gran Canaria
Authors: I. Espino  , M. Hernández
Published: May 2017

The aim of this paper is to describe and evaluate a proposal for nowcasting wind speed for wind farm locations from historical time series, based on the method of regression by support vectors. To show the improvement over other methods, we used the ANEMOS Project standard evaluation protocol for forecasting against three reference models to compare, referred to a statistical approach: persistence, autoregressive and autoregressive moving average models. The obtained results show a good performance of the proposed method and how beat the classical reference models.
Load Management for Price-based Demand Response Scheduling — a Block Scheduling Model
Authors: Ding Li  , Sudharman K. Jayaweera  , Olga Lavrova  , Ramiro Jordan
Published: May 2017

Demand Response (DR) plays an important role in electricity market design, in both reducing utility’s investment on peak generation and improving electricity bill savings and incentive payments earned by customers. Improved resource-efficiency of electricity production is achieved by closer alignment of electricity pricing information with energy consumption behaviors. In this paper, a block scheduling model of load management for price-based Demand Response is presented under two different real-time pricing schemes: linear pricing scheme and threshold pricing scheme. For linear pricing, the problem is formulated as a convex optimization problem and the optimal demand response profile is given as a two-dimensional water-filling solution either with flat water levels or different water levels for different customers. From the perspectives of the customers as a whole or as selfish individuals, the demand-response computations lead to centralized or distributed optimizations, respectively. A trade-off strategy which attempts to balance these competing objectives is also provided. This trade-off strategy divides customers into local groups within which group-wise distributed optimization is performed to improve the overall performance so that the Price of Anarchy (PoA) is reduced. For threshold pricing, which might be more applicable in certain scenarios, detailed characterization of different optimal load profiles are given assuming a discrete load unit model. A search algorithm is also proposed to find the optimal load profiles for both constant and dynamic pricing threshold scenarios. The effect of dynamic pricing threshold on customers’ electricity consumption behaviors is highlighted.
Power quality improvement using renewable energy
Authors: Gelu GURGUIATU  , Ionel VECHIU  , Toader MUNTEANU
Published: May 2017

This paper presents a three-phase Active Power Conditioner to improve power quality in microgrids based on renewable energy. Three hysteresis controllers are used to control the six IGBT bridge. In a microgrid which is a weak electrical grid the disturbances can be very important. The Active Power Conditioner (APC) presented in this paper acts as an interface between renewable energy sources and the AC bus of microgrid. The improved control strategy used offer the possibility to inject electrical energy from the renewable sources and on the other hand to improve the power quality in the same microgrid. This control strategy named Extended Indirect Control Strategy is capable to achieve better values for the following power quality indicators: THDI (Total Harmonic Distortion), PF (Power Factor), current and voltage balancing. Simulation results show the validity of the innovative control strategy
Piezoresistive Sensor for Strain Measurement on Turbine Blade with Wireless Telemetry Data Acquisition
Authors: P. Kulha  , M. Husak
Published: May 2017

In the paper, strain-gauge sensor design and its application for wireless measurement of blade deformations and strains are presented. The strain sensor was designed using FEM (Finite Element Modeling) and uses piezoresistive strain sensitive boron doped nanocrystalline layers or insulated silicon layers (SOI). Nanocrystalline Diamond (NCD) is a very promising material for fabrication of harsh-environment devices because of its unique mechanical and electrical properties. The prospective of using diamond is not only in sensors (MEMS) but in RF and power electronic as well. Selection of method for data transfer is the key problem in rotating mechanisms. Traditional approach is using the slip ring, but it is not suitable for multisensor applications due to the requirement of one slip ring per sensing element. Telemetry can be related to transfer a data over any media, but is typically applied on wireless communications. A basic telemetry system consists of a measuring element or sensor, a device for sending the transmission, a receiver, and an output controller which records and displays data.
Combustion Characteristics of CI Engine Running with Biodiesel Blends
Authors: B. Tesfa  , R. Mishra  , F. Gu  , A. D. Ball
Published: May 2017

Biodiesel is one of the promising renewable, alternative and environmentally friendly biofuels that can be used in diesel engine with little or no modification in the engine. In the present study an experimental investigation has been carried out on the combustion and performance characteristics of a CI engine running with biodiesel under steady state operating conditions. The experimental work has been conducted on a four-cylinder, four -stroke, direct injection (DI) and turbocharged diesel engine. In this investigation, biodiesel (produced from the waste oil by transesterfication process) and normal diesel have been used. During the experiment the incylinder pressure and the specific fuel consumption were measured. The experimental results of this study can be summarised as follows. The tests on engine running with different fuels (biodiesel and diesel) have resulted in almost overlapping P-V diagrams. The power output values at 1300rpm and at 105, 210, 315 and 420 Nm torque values for both the diesel and biodiesel fuels are almost the same. The engine running with biodiesel has produced slightly higher incylinder pressure and peak heat release rate than the engine running with normal diesel at all operating conditions. Furthermore, the brake specific fuel consumption values for the engine running with biodiesel are higher than the engine running with normal diesel by a maximum of 14%. However, the thermal efficiency of the engine running with biodiesel is lower than engine running by diesel by 10%.
Performances and Acoustic Noise of Model Intelligent Wind Power Unit
Authors: K. Kubo  , T. Kanemoto
Published: May 2017

The authors invented the superior wind power unit which is composed of the tandem wind rotors and the double rotational armature type generator without the traditional stator. The large-sized front wind rotor and the small-sized rear wind rotor drive the inner and the outer rotational armatures respectively, as for the upwind type. The unique rotational conditions of the tandem wind rotors and the fundamental performances were presented at the previous papers. Continuously, this paper discusses experimentally the effect of the blade profiles of tandem wind rotors on the performances and investigated the acoustic noise emitted from tandem wind rotors. The output of the tandem wind rotors with the desirable profiles is higher than the output of the traditional single wind rotor. The acoustic noise is induced mainly from the flow interaction between the front and the rear wind rotors, and is dominant at the blade passing frequency.
Semiactive Control for Floating Offshore Wind Turbines Subject to Aero-hydro Dynamic Loads
Authors: N. Luo  , C.L. Bottasso  , H.R. Karimi  , M. Zapateiro
Published: May 2017

Wind and wave dynamic loads might cause undesirable vibrations that affect the structure integrity and system performance of floating offshore wind turbines. This paper addresses the problem of dynamic load mitigation by using semiactive control techniques with the tuned liquid column dampers placed on the turbine’s tower. The control law is formulated based on the mixed H2 /H∞ methods for ensuring the system stability and reliability. Furthermore, the proposed controller only uses output feedback so as to avoid the dependence on the knowledge of the states of the system.
Using ANN to Estimate the Voltage of Unobservable Buses When One PMU or its Communication Fails
Authors: M. Gholami  , G. B. Gharehpetian  , B. Fahimi  , M. J. Sanjari
Published: May 2017

In monitoring system, the PMUs send their data to a control center. If one PMU fails or its communication fail, the data of that PMU do not send to the control center. This lack of data leads to some unobservable buses. In this paper, Artificial Neural Network (ANN) has been used to estimate the voltage of unobservable buses. We implement this method in IEEE 14-Bus.
Voltage State Estimation By ANNs with Reduction of PMUs
Authors: M. Gholami  , G. B. Gharehpetian  , B. Fahimi  , M. J. Sanjari
Published: May 2017

In this paper the estate estimation of voltage and phase of voltage has been presented. In this paper the PMU has been used to observe some part of power system and ANN (Artificial Neural Network) has been used to estimation. In this paper it is assumed that the power system is partly observable by PMUs and the network is not full observable. This method has been implemented on IEEE 14-Bus. The results show that this estimation is impossible and the error of estimation is negligible
Planning of power systems with distributed generation and storage
Authors: C. Ponce-Corral  , H. Bludszuweit  , J.A. Domínguez-Navarro
Published: May 2017

A high penetration of distributed generation in electricity networks makes it necessary to adapt the network to the new conditions of generation and consumption. Storage units can be converted within a few years in another element of power grids. Therefore, it is necessary to analyze the network to determine the optimal location of distributed generation, which lines need to be built or where to install the storage units. This paper presents a model of power network planning which takes into account the effect of the expansion of distributed generation. The results obtained show the continuing replacement of conventional generation by distributed generation and the importance of storage units in this process of replacement.
A novel approach to frequency control in an islanded microgrid by load shedding scheduling
Authors: M. Kohansal  , M. J. Sanjari  , G. B. Gharehpetian
Published: May 2017

A microgrid is composed of distributed power generation systems (DGs), distributed energy storage devices (DSs), and loads. To maintain a specific frequency in the island mode as an important requirement, the control of DGs output and charge action of DGs are used in supply surplus conditions and load-shedding and discharge action of DGs are used in supply shortage conditions. Recently, multiagent systems (MAS) for autonomous microgrid operation have been studied. Especially, load-shedding, which is intentional reduction of electricity use, is a critical problem in islanded microgrid operation based on the MAS. Therefore, effective schemes for load-shedding are required. A novel optimization algorithm called ICA has been used to optimize this load shedding procedure.
Solar Panels for Auger Southern Observatory: “SPIDERSHADOWS”
Authors: A. López Agüera  , I. Rodríguez Cabo  , D. Rey Rey  , V. Gándara Villadoniga  , M. Vázquez Garcia  , E. Vieites Montes
Published: May 2017

During the winter of 2009, technicians inform about how during a visual inspection they detect failures in the surface of different solar panels. The inspection was not casual, but due to problems with the level of charge of the batteries. Because of the aspect on the failure we will name it “spiders” (arañitas). But other anomalies, associated to the expected ageing, have been observed, like panels with blued cells, browed surface and others. In the present note, we will describe each of the observed failures, their possible causes and their effect on the solar panel operation. The full data sample we used has been obtained either on dedicated laboratory test (PAO, USC, CIEMAT) or by direct measurement in the field.
Sensorless Iterative Solar Tracking In Multiple On-Grid Photovoltaic Generators With Improved Tracking Strategy
Authors: Cittolin Guilherme F  , Mazuroski Jéssica V  , Gonçalves Rafael C  , Kroetz Marcel G  , Pece Carlo A. Z  , Santos Winderson E.
Published: May 2017

The efficiency of the energy conversion in photovoltaic panels varies according to the angle of light incidence. A new method of iterative repositioning of the panels at maximum-efficiency direction has been proposed. This method frees up the use of sun position sensors and uses the instantaneous power delivered to the power line by each panel, among a series of photovoltaic panels, as a feedback in determination of the best position in a closed-loop operation. The proposed repositioning method, as well as the repositioning dynamic of a series of photovoltaic panels, has been modeled. The system has been simulated in a single parallel-rays light source scenario. In simulations, the convergence of panels to the best energy conversion position was observed.
Computational flow field analysis of a Vertical Axis Wind Turbine
Authors: G.Colley  , R.Mishra  , H.V.Rao  , R.Woolhead
Published: May 2017

The present work has used Computational Fluid Dynamics (CFD) to obtain the flow field characteristics of a novel Vertical Axis Wind Turbine (VAWT). The turbine used in this study features a multi blade design where both a stator and rotor blade array is used. The computational model is three-dimensional and contains full-scale turbine geometry measuring 2.0m in diameter and 1m in height. The pressure field across the wind turbine has been computed for operating conditions of λ=0 and λ=0.4 where it is shown to be non-uniform. The velocity field across the turbine has been obtained at λ=0 and λ=0.4 and has highlighted the presence of a jet flow passing through the central core of the turbine as it exits the rotor assembly. It is evident that under dynamic conditions and due to the direction of this jet flow a strong flow interaction occurs with the downstream rotor blades. This interaction results in rotor blades 5, 6 and 7 generating an opposing torque that acts against the direction of motion. Furthermore, it is noticed that rotor blades 10, 11, 12 and 1 contribute to the majority of overall rotor torque, which is a characteristic of this machines design.
Design of a Monitoring and Test system for PV based Renewable Energy Systems
Authors: S. Berberkic  , P.J. Mather  , V. Holmes  , M. Sibley
Published: May 2017

To optimize the energy production and usage, of a Renewable Energy System (RES), it is essential that an effective monitoring and control strategy is employed. In order to develop new control algorithms the designer needs to evaluate the RES parameters and at the same time simulate real test condition load profiles. The developed system is composed of a monitoring tool that measures and displays, in real-time, the parameters of PhotoVoltaic (PV) solar panels, and of an electronic load that can simulate load profiles such as the averaged domestic or stepped power consumption. The monitoring system is implemented using a µcontroller and the electronic load is composed of a MOSFET, driven using a Pulse Width Modulated (PWM) output of a PIC µcontroller. Furthermore, the power consumption profiles are stored in the internal memory of the PIC µcontroller. The obtained results demonstrate the ability of the system to monitor the current, voltage and temperature of PV panels as well as the ability to simulate different electronic load profiles.
A semi-empirical procedure for the evaluation of multi-stage turbine performances
Authors: D. Barsi  , R. Canepa  , A. Satta
Published: May 2017

The available tools for the analysis of fluiddynamic processes inside turbomachines are nowadays extremely powerful and versatile. Despite this, the use of simplified procedures, such as the 2D meridional approach, is still relevant, due to its great running simplicity and good accuracy. The full three-dimensional analysis, in fact, even if it could model thoroughly details the fluid-dynamic phenomena occurring in turbomachines, requires huge computational resources and longer computational times with respect to two-dimensional approaches, and this is justified only after a simplified preliminary study of the machine. Also management simplicity, consistence of the required data and usability of results are aspects that should not be ignored, above all for the possibility of creating tools easily available for turbomachines designers. A through flow method, formulated in terms of pressure rather than velocity, for the analysis of multistage axial turbines is presented. It is designed to provide reliable radial distributions of circumferentially averaged values for the fundamental unknowns. The proposed form of the radial equilibrium equation can represent also sharp velocity gradients in radial direction and deal with very realistic situations as discussed in the applications presented. The code has been used for the analysis of both an experimental multistage gas turbine and an industrial steam turbine. The results obtained have been compared with the circumferentially averaged results of a viscous fully 3D commercial code.
Energy response of a mono-axis tracked solar thermal collector with vacuum tubes
Authors: V.E. Dombi  , I. Visa  , D.V. Diaconescu  , M.M. Vatasescu  , N.I.Tatu
Published: May 2017

. Looking towards a sustainable future, Transilvania University of Brasov develops many projects on diverse renewable energy conversion systems; this paper presents a solar tracked solar thermal collector (STC) system, designed for a future implementation on Transilvania University campus. The specific requirement is that the STC system has to be configured to keep a zero energy response during the summer holydays (when the energy consumption is null). The proposed solution describes a mono-axial solar tracking system designed to perform an annual step wise tracking program to capture the most of the available solar energy using a solar thermal collector (STC) with vacuum tubes. The tracking program represents an optimised step tracking law developed in dependence with the diurnal movement of the sun. Numerical simulations are done for one year interval, for Brasov Romania geographic site, to evaluate the daily variations of: the pseudo-equatorial solar angles (γ, β); the pseudo-equatorial tracking angles (γ*, β*); the incidence angle; the available beam solar radiation (B) and the beam received solar radiation by the STC system (B*). The energy response of the tracked STC, for Brasov, Romania, is evaluated considering both clear sky and cloudy sky conditions, while neglecting the diffuse radiation effect.
A SINGLE STAGE DC-DC CONVERTER FEASIBLE TO BATTERY CHARGING FROM PV PANELS WITH HIGH VOLTAGE STEP UP CAPABILITY
Authors: Paulo P. Praça  , Gustavo A. L. Henn  , Ranoyca N. A. L. S  , Demercil S. Oliveira  , Luiz H. S. C. Barreto
Published: May 2017

This paper presents a dc-dc power converter integrated in such a way to obtain, in a single conversion stage, the maximum energy extraction from photovoltaic panels, battery charging and discharging dynamic control, and high voltage step-up to feed the inverter DC bus, also operating with soft-switching capability. Although this idea can be applied to most of the high voltage gain topologies, this paper is based on a structure derived from the half-bridge boost converter. Thus, a 500W prototype, with input voltage of 24V and output voltage of 200V, has been developed with the purpose of obtaining the experimental results and validate the proposed converter. High efficiency is achieved, above 92.5%, confirming the expected operation and functionalities necessary for the proposed application.
The Wind Energy apply to Water Pumping in Isolated Place
Authors: J. Nóbrega  , T. Araújo
Published: May 2017

The stead-state analysis of Wind Energy Conversion Systems, consisting on windmill, synchronous generator, transmission line and induction motor driving a centrifugal pump is developed. The performance of the system operating at variable speed with a flux control is examined using mathematical models and digital simulation. The control scheme is proposed and tested in laboratory and a test center to compare field results with simulation results.
A Novel Method to Eliminate Negative Time Period of SVPWM using DSP TMS320F2812
Authors: Ronad B. F  , Naik R. L.  , Jangamshetti Suresh.H
Published: May 2017

Conventional SVPWM method generates negative time period during lower switching frequency at higher voltage magnitudes. This paper presents a simplified method for implementation of Space Vector PWM technique for two level VSI using DSP TMS320F2812. Methodology presented is to implement SVPWM without lookup table and to calculate time periods independent of voltage magnitude. Experimental results show that proposed method overcomes problem of negative time period for said conditions. An experimental setup is developed in the laboratory around TMS320F2812 to obtain and verify the desired results. This work is a part of project titled “Development of FPGA-DSP Controlled Multilevel Inverter Interface for Grid connection of Wind Turbine Generators” funded by AICTE New Delhi.
A computational method to optimize energy savings of tension structures set in road tunnels
Authors: L.M. Gil-Martín  , A. Peña-García  , R. Escribano  , A. Espín-Estrella
Published: May 2017

After the successful introduction of transparent tension structures in the portal of road tunnels as an effective measure for energy savings, optimization of such savings has been sought. A computational method based on graphical design capable to simulate the optical properties of the sun, any transparent tension structure and any road tunnel whatever its orientation, has been developed and presented in this paper. A comparison with measurements in a real tension structure placed in the entrance portal of one real tunnel is performed and discussed.
Dual frequency system for power-demanding measurement in the isolated areas
Authors: A. Boura  , M. Husak
Published: May 2017

The paper presents solution for wireless and battery-less measurement in the enclosed areas. The principle is based on previous work, while this paper is focused on high power-demanding applications such as MEMS accelerometers, gas sensors, piezoresistive strain gauges, etc. It can be suitable for continuous wireless and battery-less measurement in isolated systems such as the rotating objects, concrete walls, enclosed barrels, high temperature chambers etc. It is based on near magnetic field coupling in radiofrequency band. The principle is similar to the RFID, while it is more powerful and the powering and signal transfer is separated by the different frequencies. The antennas are designed for surface mounting. The system is desired to be used in long-term monitoring of the environment.
Some Procedures in Mitigating Conducted Electromagnetic Interference
Authors: M. I. Buzdugan  , H. Bălan  , T. I. Buzdugan
Published: May 2017

In our opinion, the problem of conducted interference generated by power converters, represents not a simply mater of harmonics or even interharmonics, as usually is considered, but really a broader issue, which requires a careful treatment of a continuous spectrum of frequency, extending until 30MHZ. The following paper presents a conducted electromagnetic interference problem in the case of a power converter, included in one kinetic therapy equipment (actually a treadmill). Analysis is made, considering only conducted emissions at the mains supply port of the equipment. Tests carried out, outlined a few procedures in the analysis and mitigation of electromagnetic conducted interferences using electromagnetic interference mains filters. Virtually all products contain a power supply filter as the last circuit that noise currents pass through before they exit the product through the power cord. Sometimes, properly designed transformers can provide inherent filtering, and so can obviate the need for an intentional filter. In other cases, like the one presented in the paper, mains filters are not enough for mitigating conducted interferences and they must be replaced, or simpler retrofitted by an additional one, the filters’ cascade being able more often to mitigate perturbations. Mains passive EMI filters carry potentially high currents at dangerously high voltages, so the choice of these filters is an essential issue. From the paper it can be seen that the EMI filter issues should be considered with careful attention by designers, because they are not only ancillary devices, as they are more often treated.
An Optimal Virtual Inertia Controller to Support Frequency Regulation in Autonomous Diesel Power Systems with High Penetration of Renewables
Authors: Miguel Torres  , Luiz A.C. Lopes
Published: May 2017

This paper addresses the problem of frequency control in autonomous diesel-based power system with high penetration of renewables. Usually, small power systems with high penetration of renewable energies are supplied by one or two small diesel generators, resulting in a system with a relatively low moment of inertia, and which can be susceptible to significant frequency variations. However, frequency regulation can be supported by modifying the inertial response of the system in an artificial way, i.e., by adding a virtual inertia. The latter can be performed by controlling the power electronics interface of a distributed generator or an energy storage unit. In this work, a controller is designed to provide the optimal virtual inertia which minimizes, according to the proposed performance index, variations in the fundamental frequency as well as in the power flow through the energy storage system. The optimal controller is compared by simulations with other virtual inertia control strategies.
Modeling, Simulation and a Comparative study between a Single-phase Switched Reluctance Machine (6x6) and a Three-phase Switched Reluctance Machine
Authors: Dias, R. J  , Andrade D.A.  , Cabral L.G  , Silveira A.W.F.V  , Silveira A.F.V  , Gomes  L.C  , Bissochi C. A
Published: May 2017

The comparative study of electric machines has been in vogue due to the growing demand for electromechanical converters with maximum possible efficiency. In this scene, the switched reluctance machines have proven to be competitive. Comparative studies between these machines and the already established induction machines can be easily found in the scientific literature, but studies on various configurations of the switched reluctance machines are not as widespread. This paper shows the modeling, simulation and presents a comparative study of two Switched Reluctance Machines to a single phase (6x6) and three phase (6x4). Aspects of construction, drive and efficiency are discussed in order to find advantages and disadvantages to each of these machines.
Maximum Torque per Ampere Operation of Brushless Doubly Fed Induction Machines
Authors: M. Ahmadian  , B. Jandaghi  , H. Oraee
Published: May 2017

In this paper, an analytical method for increasing the steady state torque per ampere capability for BDFMs, using equivalent circuit is presented. In this approach, uni-current proposition proposed to define a unique current value for optimization, and find the current angel corresponding to maximum torque. The accuracy of the proposition is verified by simulation. The effect of pole pair number selection of power and control windings on maximum torque is explained by dividing torque expression into synchronous and asynchronous terms. Finally, the optimal current values and optimal torque are achieved. Based on the optimal value of torque, or MTPA index, analytical optimization of machine design is suggested, which can be performed by manipulation of components of the MTPA index
Renewable Energy Policy and Market Developments in Kosovo
Authors: N. Avdiu  , A. Hamiti
Published: May 2017

The paper highlights and analyzes the renewable energy policy instruments and market developments in Kosovo, with the aim of highlighting policy design and implementation lessons relevant to the wider and faster replication of RES (renewable energy sources) in Kosovo. The promotion of electricity from renewable energy sources is a high priority for several reasons. First of all the obligation rise from Kosovo’s membership in the Energy Community Treaty of South East Europe, the security and diversification of energy supply, environmental protection and social and economic cohesion. RES-E (renewable energy sources - Electricity) penetration, support schemes and certificate of origin will be presented in the context of Kosovo energy market. Successful policies also take into account real market factors and barriers, the need for simplicity and accountability, minimum costs and profitability levels.
Investigation on the impact of design wind speed and control strategy on the performance of fixed-pitch variable-speed wind turbines
Authors: X. Liu  , L. Wang  , X. Tang
Published: May 2017

Wind turbine blade design optimization remains one of the fundamental research areas for modern wind turbine technology. The general design process for fixed-pitch variablespeed wind turbine blades assumes the rated wind speed as the design wind speed. However, for a fixed-pitch wind turbine with fixed rotor diameter and rated power at rated speed, we do not know the optimum design wind speed, which should be used for the calculation of the wind turbine blade parameters based on a particular aerofoil for a specific site with low annual mean wind speed. This paper investigates the impact of design wind speed and control strategy on the performance of fixed-pitch wind turbines through a set of design case studies. The design wind speeds are considered at the more prevalent wind speeds than the rated wind speed. Three different control strategies are addressed, i.e. maximum power point tracking, mixture of variable-speed and fixed-speed, and over-speeding. Annual energy production, blade manufacturing cost, aerodynamic load performance and cost of energy are analyzed and compared using the design case studies. The results reveal a clear picture in determining the optimum design wind speed and control strategy for both maximizing annual energy production and minimizing cost of energy.