Somewhat Homomorphic Encryption Technique with its Key Management Protocol

Cloud computing has been contemplated as the architecture of various Business organizations, providing easy access to vast data storage and applications services. Most of the cloud service providers encrypt the data only on the network , while some even store the data in encrypted format. This means anyone with access to the cloud servers (cloud service providers) can appropriate it. Even if the data is encrypted during storage, keys are often stored along with your data .Thus an end-to-end encryption scheme has been proposed as a promising solution to data storage on cloud ,in order to perform computations on the encrypted data and thereby store the key securely. Somewhat Homomorphic Encryption is a fully homomorphic encryption technique which is compact, semantically secure with significantly smaller public key and is capable of encrypting integer plaintexts rather than single bits, with comparatively lower expansion and computational complexities Keywords-Cloud computing, Cryptography, Homomorphic Key Management (HKM), Homomorphic encryption, Somewhat Homomorphic encryption(SHE)

Review on recent trend of solar photovoltaic technology

Solar photovoltaic technology is one of the renewable technologies, which has a potential to shape a clean, reliable, scalable and affordable electricity system for the future. This article provides a comprehensive review of solar photovoltaic technology in terms of photovoltaic materials efficiency and globally leading countries. Based on past years review and photovoltaic installations in the year 2014, the major five leading countries identified are China, Japan, USA, Germany and UK. These five countries altogether accounted for 80% of photovoltaic installations in 2014. The article also discusses the driving policies, funding and Research and Development activities: to gauge the reasons behind the success of the leading countries. Finally, this article reviews the photovoltaic cost analysis in terms of the photovoltaic module cost, balance of system cost and project cost with the help of listed 98 globally installed projects

Enhancement of Albedo for Solar Energy Gain with Particular Emphasis on Overcast Skies

In the absence of ground reflected radiation measured data, an average albedo value of 0.2, which describes the reflective properties of the bare ground is generally used. The variation of albedo based on different foreground surfaces and under different atmospheric conditions is an area which is under research. This paper presents an experimental investigation of albedos of different foreground materials that can be used for photovoltaic (PV) applications. Overcast skies are predominant in northerly locations and will have a high frequency of low solar altitudes, and thus ground reflection is an important contributor towards total solar energy gain. The foreground surfaces include common materials: Grass, sand, and cement slabs, and some non-conventional materials: White pebbles, white boards, white tiles, and aluminium foil. The impact of factors, such as ageing, solar elevation, rain, and cloud cover (sky conditions) is analysed to determine the changes in albedos of these materials. Each material was observed to have individual performance characteristics under these factors. It was found that the non-conventional materials were least prone to weather-related changes and have higher albedo values as compared to the conventional materials, and also have good potential to replace the conventional materials for any given PV application

Installation of roof-top solar PV modules and their impact on building cooling load

It has been shown by many researchers that over a long term there has been a slow but steady rise of ambient temperature within the Indian sub-continent. Due to an increased economic prosperity there has been an accompanied increase in the urban heat island effect. Furthermore, urbanisation of large cities in India has also led to higher population densities. The above factors had the combined effect of a significant increase of cooling load of buildings. The high density of dwellings and other building construction has resulted in shading of walls. However, the flat roof spaces are exposed to an uninterrupted solar radiation regime and this in turn leads to generation of high sol-air temperatures which cause higher cooling loads. Presently, it has been argued that roof spaces are one of the major contributors to building cooling load.In this article the reasons behind the phenomenal rise in the installation of air-conditioners in India are reviewed. The dual role of roof-top PV systems in electricity generation and reduction of building cooling load due to the shading they provide is then investigated. For this purpose, the CIBSE method to obtain sol-air temperature with solar radiation and outdoor ambient temperature has been used. Sol-air temperature for five key Indian locations (Delhi, Bhopal, Ahmadabad, Bhubaneswar and Chennai), based on the recently presented data by the NREL-India Meteorological Department consortium, were then obtained. A computer simulation routine was presently developed for solving the classical transient heat conduction problem with hourly sol-air temperature data and roof construction details provided to the routine. This program was executed to obtain the cooling load profile for each of the five Indian locations for the respective design day.Practical application: The present work reviews the reasons behind the phenomenal rise in the installation of air-conditioners in India. The dual role of roof-top PV systems in electricity generation and reduction of building cooling load due to the shading they provide has been investigated. The computer simulation demonstrated that the energy required for roof-induced cooling load decreased between 73-90% after installation of the PV system. The method used in this work has the advantage that it enables the user to obtain cooling load estimates using a general transient heat conduction Roof-top solar PV module installation approach. Moreover, all software was developed within MS-Excel environment, this is also an additional advantage as the cost associated with purchase and training of proprietary building energy software can be prohibitive for many consultants who are based in developing countries

Solar PV generation enhancement using radiation augmentation from improved reflectance horizons

The total incident irradiation on a surface such as a photovoltaic (PV) module is the sum of beam, sky-diffuse and ground reflected radiation. Ground albedo or ground reflectance is defined as the ratio between the ground reflected radiation and the global incident radiation. A constant albedo value of 0.2 for bare ground and 0.5 for dry tropical localities is widely accepted and is used in the modelling of PV systems. The real albedo values of foreground surfaces are different and hence using a constant value may be unsuitable to accurately predict the output of PV systems. This research investigated the real albedo values of various foreground surfaces and how it is affected by the factors such as ageing, solar altitude, rain and cloud cover (sky conditions). To investigate the impact of such factors, an experiment was setup to measure the albedo of conventional foreground materials (grass, sand and cement) and non-conventional materials (white pebbles, white paint, white tiles and aluminium foil). These materials were selected based on the type of PV applications such as solar farms and Building Applied Photovoltaic. The measured average albedo values of grass, sand, cement, white pebbles, white paint, white tiles and aluminium foil were 0.20, 0.36, 0.56, 0.15, 0.70, 0.61 and 0.73 respectively. Research has shown that non-conventional materials, increased the slope irradiation and ultimately the energy generation of PV modules. These results were further validated using the long-term data from the Garston and Edinburgh database. Lastly, a new computational tool was developed, which considers various albedo values of foreground materials simultaneously for any tilt angle of a PV module to compute the ground-reflected component

Performance of solar PV systems

Paikallisesti nenään käytetty kortikosteroidisumute on pitkittyneen nenän sivuontelotulehduksen ensisijainen hoitomuoto. Tämän hoitomuodon suurin ongelma on, ettei nenäkäytävään sumutettu lääkeaine pääse suljettujen, sairaiden sivuonteloiden sisälle, jolloin hoidon teho jää osittaiseksi. Leikkaussaliolosuhteissa suoraan seulalokeroiden sisälle asetettava lääkeannostelija Relieva StratusTM MicroFlow Spacer (Relieva Stratus) vapauttaa kortikosteroidia paikallisesti, jolloin sairastuneiden sivuonteloiden sisälle saadaan korkea lääkepitoisuus. Tämän väitöskirjan tarkoituksena on selvittää Relieva Stratus-lääkeannostelijan tehoa ja turvallisuutta verrattuna samaa kortikosteroidia sisältävään nenäsumutteeseen pitkittynyttä sivuontelotulehdusta sairastavilla potilailla. Lisäksi halutaan arvioida, voidaanko lääkeannostelijaa käyttämällä vähentää laajempaa ja riskialttiimpaa sivuontelokirurgiaa, ja onko leikkausnavigaattoriavusteinen tekniikka läpivalaisutekniikkaa käyttökelpoisempi lääkeannostelijan asetuksessa. Tutkimukseen valittiin 63 aikuista potilasta, joilla oli todettu kartiokeilatietokonetomografialla varmistettu pitkittynyt sivuontelotulehdus, ja joiden oli arvioitu hyötyvän sivuonteloleikkauksesta. Potilaat satunnaistettiin kahteen ryhmään sukupuolen, iän, astman, nenäpolypoosin ja tupakoinnin suhteen. Lääkeannostelijaryhmälle (34 henkilöä) asennettiin triamsinoloniasetonidia (Kenalog40® 40 mg/ml) vapauttava lääkeannostelija molemmille puolille seulalokeroihin. Nenäsumuteryhmä (29 henkilöä) käytti samaa kortikosteroidia sisältävää nenäsumutetta (Nasacort® 55ug/annos) kuuden kuukauden ajan. Läpivalaisutekniikalla lääkeannostelija asetettiin 13 ensimmäiselle potilaalle ja lopuille 21 potilaalle käyttäen leikkausnavigaattoria. Päämuuttuja tutkimuksessa oli nenän ja nenän sivuonteloiden sairauksiin kehitetty tautikohtainen oire- ja elämänlaatumittari SNOT-22. Oireita arvioitiin myös Visual Analogue Scale (VAS) -mittarilla. Lisäksi potilaita tutkittiin sivuonteloiden kartiokeilatietokonetomografiatutkimuksella, nenän tähystyksellä sekä nenän virtaus- ja tilavuustutkimuksilla. Seurantakäynnit toteutettiin kolme ja kuusi kuukautta hoidon aloituksen jälkeen. Kolme vuotta tutkimuksen jälkeen kartoitettiin, oliko potilaille tehty tutkimuksen jälkeen sivuonteloleikkauksia. Tutkimuksen päättyessä tutkimuksessa oli mukana yhteensä 57 potilasta (28 lääkeannostelijaryhmässä, 29 nenäsumuteryhmässä). Molempien ryhmien potilaiden oireet vähenivät ja elämänlaatu parani SNOT-22- mittarilla mitattuna sekä kolmen että kuuden kuukauden kuluttua hoidon aloittamisesta. Ryhmien välillä ei todettu tilastollisesti merkitsevää eroa. Oireet vähenivät molemmissa ryhmissä myös VAS-mittarilla arvioituna. Nenäsumuteryhmässä havaittiin molemmilla seurantakäynneillä tilastollisesti merkitsevä nenäkäytävän kokonaistilavuuden kasvu. Vastaavaa kasvua ei havaittu lääkeannostelijaryhmässä ja tämä tulos oli ainoa, jossa löydettiin tilastollinen ero tutkimusryhmien välillä. Lähes puolet molempien ryhmien potilaista ei enää tarvinnut sivuonteloleikkausta hoidon aloitusta seuranneen puolen vuoden seurantajakson jälkeen. Potilaan tupakointi lisäsi leikkaushoidon tarvetta; tupakoivista potilaista leikkaushoitoon päätyi 74% ja tupakoimattomista 42%. Hoidon teho vaikutti säilyvän, sillä kolmasosalle tutkimukseen osallistuneista potilaista ei tehty sivuonteloleikkausta kolmen vuoden tutkimuksen aikana. Tutkimusryhmien välillä ei todettu tilastollisesti merkitsevää eroa leikkaukseen hakeutumisessa. Leikkausnavigaattoria käyttäen lääkeannostelija pystyttiin ohjaamaan tarkasti haluttuun sivuonteloon. Läpivalaisutekniikalla ei päästy yhtä tarkkaan lopputulokseen. Lisäksi läpivalaisutekniikka, toisin kuin leikkausnavigaattori, edellyttää potilaalle ja henkilökunnalle haitallisen röntgensäteilyn käyttöä. Näin ollen leikkausnavigaattoriavusteista tekniikkaa voitiin pitää kokonaisuudessaan käyttökelpoisempana ja turvallisempana menetelmänä. Uuden lääkeannostelijan käyttö oli helppoa ja turvallista. Merkittäviä haittavaikutuksia ei havaittu asetuksen yhteydessä tai myöhemmin seurannan aikana. Potilaiden oireet vähenivät ja elämänlaatu koheni sekä lääkeannostelija- että nenäsumuteryhmässä. Koska varsin kalliin lääkeannostelijan asettaminen seulalokeroihin vaatii leikkaussaliolosuhteet, läpivalaisun tai leikkausnavigaattorin käytön, ja sisältää mahdollisuuden haittavaikutuksiin, ei lääkeannostelijan käyttöä voida suositella pitkittyneen sivuontelotulehduksen ainoana hoitomuotona. Vastaavaan hoitotulokseen voidaan päästä turvallisemmalla ja varsin edullisella kortikosteroidinenäsumutteen käytöllä. Kiinnittämällä huomiota nenäsumutteen lääkkeenottotekniikan opetukseen, ja kannustamalla potilasta lääkkeen säännölliseen käyttöön, voidaan parantaa pitkittyneen sivuontelotulehduksen hoitotuloksia, sekä parhaassa tapauksessa leikkaushoidon tarve häviää lähes joka toiselta potilaalta.Topical corticosteroid therapy is the first-line treatment of chronic rhinosinusitis (CRS). The topical administration route of nasal sprays or drops often leads to suboptimal drug delivery inside the paranasal sinuses and correspondingly to suboptimal treatment results. The Relieva StratusTM MicroFlow Spacer is a drug- eluting stent (DES) that is temporarily implanted into the ethmoid sinus to provide local and targeted delivery of the corticosteroid to the mucosa in order to relieve symptoms and avoid sinus surgery. The aim of this prospective, randomised, clinical study was to compare the efficacy and safety of the DES and optimally dosed, regularly used topical intranasal corticosteroid (ICS) spray therapy in patients with CRS. Further, to evaluate whether image-guided navigation (IGS)-assisted DES insertion into the ethmoid sinus would prove to be more useful than fluoroscopic guidance. And finally, to evaluate whether a DES implanted in the ethmoid sinuses can prevent sinus surgery. Sixty-three adult patients (44 women, 19 men) with ethmoidal involvement in cone beam computed tomography (CBCT) whose first-line medical treatment with topical ICSs had failed and who were candidates for endoscopic sinus surgery (ESS) were randomised into two groups with the following parameters: age, sex, asthma, nasal polyposis, and the use of tobacco. Patients in the DES group (n=34) received stents filled with 24 mg of triamcinolone acetonide (Kenalog40®) solution on both sides, whereas patients in the nasal spray group (n=29) used triamcinolone acetonide nasal spray (Nasacort® 55ug/dose) 2 doses/day on both sides for six months. The first 13 patients were implanted with DES by using fluoroscopy and the remaining patients underwent IGS-assisted DES insertion. The main outcome variable was the 22 item Sinonasal Outcome Test (SNOT-22). Visual analogue scale (VAS), direct nasal endoscopy, and rhinometric measurements were performed at the beginning of the study, and after three months and six months of follow-up. CBCT imaging of the paranasal sinuses was performed before the therapeutic interventions and at the end of the follow-up period. Patients were followed up prospectively for six months and at 36 months to find out whether they had undergone ESS. A total of 57 patients (DES n=28, nasal spray n=29) were available for analysis at both timepoints. Both treatment modalities significantly improved quality of the life (QoL) as measured with SNOT-22 score with no significant difference being found between the two groups. The VAS score decreased in both groups – improvements were significant at three and six months in the nasal spray group, but a significant difference was noted only at three months in the DES group. There was a statistically significant increase in total nasal cavity volumes in the ICS spray group, but not in the DES group. No other differences in the mean total resistance in rhinomanometry, endoscopic score or Lund-Mackay staging system score was found between the groups. ESS could be prevented in almost half of the patients in both groups at 6 months (DES 13/28, 46%, nasal spray 14/29, 48%). At 36 months, 20/28 (71%) of the patients in the DES group and 18/29 (62%) in the nasal spray group had been operated. There were no significant differences between the groups at either timepoint. Fourteen of the 19 (74%) smokers and 16 of the 38 (42%) non-smokers were operated at the 6-month timepoint (p=0.024). There were no immediate or delayed complications or significant adverse effects. The IGS-assisted approach improved the accuracy of the insertion and made it possible to treat precisely the diseased cells identified in preoperative CT imaging. We found the insertion of the DES easy and safe to perform. Due to radiation protection concerns, the complexity and variability of ethmoidal cavity anatomy and the vital anatomical structures surrounding the ethmoidal cells, we recommend the use of optical IGS in the insertion. Patients benefitted from both DES and ICS spray and QoL improved in both groups. We could not find any significant difference between the treatments except the greater increase in the total nasal cavity volumes favouring the nasal spray group. In the medium term (6 months), ESS can be prevented by both therapies in almost half of cases. This preventive effect was, however, somewhat diminished in the long term (36 months). These results emphasise the importance of optimal dosing technique, motivation and regular, long-term administration of topical ICS therapy in the primary treatment of CRS. Because of the good results for the nasal spray and the much higher material and operating room costs associated with the DES, we cannot recommend the use of the DES over nasal spray as a monotherapeutic treatment for CRS

Battery Crush Test Procedures in Standards and Regulation: Need for Augmentation and Harmonisation

Battery safety is a prominent concern for the deployment of electric vehicles (EVs). The battery powering an EV contains highly energetic active materials and flammable organic electrolytes. Usually, an EV battery catches fire due to its thermal runaway, either immediately at the time of the accident or can take a while to gain enough heat to ignite the battery chemicals. There are numerous battery abuse testing standards and regulations available globally. Therefore, battery manufacturers are always in dilemma to choose the safest one. Henceforth, to find the optimal outcome of these two major issues, six standards (SAE J2464:2009, GB/T 31485-2015:2015, FreedomCAR:2006, ISO 12405-3:2014, IEC 62660-2:2010, and SAND2017-6295:2017) and two regulations (UN/ECE-R100.02:2013 and GTR 20:2018), that are followed by more than fifty countries in the world, are investigated in terms of their abuse battery testing conditions (crush test). This research proves that there is a need for (a) augmenting these standards and regulations as they do not consider real-life vehicle crash scenarios, and (b) one harmonised framework should be developed, which can be adopted worldwide. These outcomes will solve the battery manufacturers dilemma and will also increase the safety of EV consumers

End of electric vehicle batteries: reuse vs. recycle

It is a fact that electric vehicles (EVs) are beneficial for climate protection. However, the current challenge is to decide on whether to reuse an EV battery or to recycle it after its first use. This paper theoretically investigates these areas i.e., recycle and reuse. It was found that there are several commercially used recycling processes and also some are under research to regain maximum possible materials and quantity. The concept of reusing (second life) of the battery is promising because, at the end of the first life, batteries from EVs can be used in several applications such as storing energy generated from renewable sources to support the government grid. However, the cost and life-cycle analysis (LCA) demonstrated that there are several aspects involved in battery reuse applications. Henceforth, one LCA generalised method cannot provide an optimal approach for all cases. It is important to have a detailed study on each of the battery reusing applications. Until then, it is safe to say that reusing the battery is a good option as it would give some time to recycling companies to develop cost and energy-efficient methods.Peer ReviewedObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats Sostenibles::11.6 - Per a 2030, reduir l’impacte ambiental negatiu per capita de les ciutats, amb especial atenció a la qualitat de l’aire, així com a la gestió dels residus municipals i d’altre tipusObjectius de Desenvolupament Sostenible::12 - Producció i Consum ResponsablesObjectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables::12.2 - Per a 2030, assolir la gestió sostenible i l’ús eficient dels recursos naturalsObjectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables::12.4 - Per a 2020, aconseguir la gestió ecològicament racional dels productes químics i de tots els residus al llarg del seu cicle de vida, de conformitat amb els marcs internacionals convinguts, i reduir-ne de manera significativa l’alliberament a l’atmosfera, a l’aigua i al sòl a fi de minimitzar-ne els efectes adversos sobre la salut humana i el medi ambientObjectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables::12.5 - Per a 2030, disminuir de manera substancial la generació de residus mitjançant polítiques de prevenció, reducció, reciclatge i reutilitzacióObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesPostprint (published version

End of Electric Vehicle Batteries: Reuse vs. Recycle

It is a fact that electric vehicles (EVs) are beneficial for climate protection. However, the current challenge is to decide on whether to reuse an EV battery or to recycle it after its first use. This paper theoretically investigates these areas i.e., recycle and reuse. It was found that there are several commercially used recycling processes and also some are under research to regain maximum possible materials and quantity. The concept of reusing (second life) of the battery is promising because, at the end of the first life, batteries from EVs can be used in several applications such as storing energy generated from renewable sources to support the government grid. However, the cost and life-cycle analysis (LCA) demonstrated that there are several aspects involved in battery reuse applications. Henceforth, one LCA generalised method cannot provide an optimal approach for all cases. It is important to have a detailed study on each of the battery reusing applications. Until then, it is safe to say that reusing the battery is a good option as it would give some time to recycling companies to develop cost and energy-efficient methods

Analysis of Deactivation of 18,650 Lithium-Ion Cells in CaCl₂, Tap Water and Demineralized Water for Different Insertion Times

The deployment of battery-powered electric vehicles in the market has created a naturally increasing need for the safe deactivation and recycling of batteries. Various deactivating methods for lithium-ion cells include electrical discharging or deactivation with liquids. Such methods are also useful for cases where the cell tabs are not accessible. In the literature analyses, different deactivation media are used, but none include the use of calcium chloride (CaCl2) salt. As compared to other media, the major advantage of this salt is that it can capture the highly reactive and hazardous molecules of Hydrofluoric acid. To analyse the actual performance of this salt in terms of practicability and safety, this experimental research aims to compare it against regular Tap Water and Demineralized Water. This will be accomplished by performing nail penetration tests on deactivated cells and comparing their residual energy against each other. Moreover, these three different media and respective cells are analysed after deactivation, i.e., based on conductivity measurements, cell mass, flame photometry, fluoride content, computer tomography and pH value. It was found that the cells deactivated in the CaCl2 solution did not show any signs of Fluoride ions, whereas cells deactivated in TW showed the emergence of Fluoride ions in the 10th week of the insertion. However, with the addition of CaCl2 in TW, the deactivation process > 48 h for TW declines to 0.5–2 h, which could be an optimal solution for real-world situations where deactivating cells at a high pace is essential