Comparison between Energy Simulation and Monitoring Data in an Office Building

One of the most important steps in the retrofitting process of a building is to understand its pre-retrofitting stage energy performance. The best choice for carrying this out is by means of a calibrated building energy simulation (BES) model. Then, the testing of different retrofitting solutions in the validated model allows for quantifying the improvements that may be obtained, in order to choose the most suitable solution. In this work, based on the available detailed building drawings, constructive details, building operational data and the data sets obtained on a minute basis (for a whole year) from a dedicated energy monitoring system, the calibration of an in-use office building energy model has been carried out. It has been possible to construct a detailed white box model based on Design Builder software. Then, comparing the model output for indoor air temperature, lighting consumption and heating consumption against the monitored data, some of the building envelope parameters and inner building inertia of the model were fine tuned to obtain fits fulfilling the ASHRAE criteria. Problems found during this fitting process and how they are solved are explained in detail. The model calibration is firstly performed on an hourly basis for a typical winter and summer week; then, the whole year results of the simulation are compared against the monitored data. The results show a good agreement for indoor temperature, lighting and heating consumption compared with the ASHRAE criteria for the mean bias error (MBE).

ASSESSMENT OF SOLAR ENERGY POTENTIAL FOR A RADIALLY STAGGERED HELIOSTATS FIELD USING SUN TRACKING METHOD

This article deals with the potential assessment of tower type solar thermal power system. An algorithm was developed to employ sun-tracking method, which provides the characteristic angles of the heliostats such that the incoming beams of sun rays are reflected to the receiver. A suite of MATLAB code was developed to implement the mathematical models for a quick evaluation of solar energy potential in a radially staggered heliostat field for the capital city of Kingdom of Saudi Arabia, Riyadh. An existing clear-sky model in the literature was used to compute hourly insolation. Optical efficiencies and heat collected by the receiver (from individual heliostat in the field on hourly basis) were computed and the monthly-averaged daily results were presented zone-wise and for the complete heliostat field. It was observed that the optical efficiency of the heliostat decreases with increasing distance from the receiver tower; this was due to increasing spillage of the reflected rays and decreasing cosine efficiency with increasing distance of the heliostat from the receiver tower. Results showed that annual average optical efficiency of the field is nearly forty-nine percent.

Keratitis Treatment by Removal of Concealed Retrocorneal Plant Foreign Body

Purpose: We report a case of keratitis that improved after removal of a causative plant foreign body from below the posterior surface of an opaque cornea. The foreign body was revealed by anterior segment optical coherence tomography (AS-OCT) and gonioscopy.Case summary: A 79-year-old woman was referred with an impression of left-eye keratitis; the eye had been injured by a branch of a tangerine tree 1 month prior. She had been given the usual topical antibiotics by a local clinic, but they were ineffective. At her initial visit, her visual acuity was only hand motion in the left eye; slit-lamp examination revealed a 3 × 3-mm corneal infiltration with a hypopyon in the anterior chamber. Despite administration of strong topical antibiotics on an hourly basis, the corneal lesion worsened. AS-OCT and gonioscopy revealed a small foreign body below the posterior surface of the cornea; this was surgically removed. The corneal opacity and corneal epithelial defects dramatically improved, and the hypopyon disappeared.Conclusions: The possibility of a residual foreign body should be considered if trauma precedes infectious keratitis that does not improve with conventional treatment and the posterior surface of the cornea is not visible because of corneal opacity. In such a case, AS-OCT and gonioscopy can be useful.

Simulation model of natural gas supply chain in a function of costs optimization: the case of Croatia

The purpose of this study is to develop a natural gas simulation model for costs optimization. The main focus of the model is on the transmission system since its imbalance leads to the penalties which must be paid by the suppliers. The total nominated amount of natural gas (the gas injected into the transmission system) must be consumed (withdrawn from the system) in order for the system to be in balance. In practice, this is not the case since it is very hard to accurately predict the future hourly consumption (in order to make a nomination) and certain deviations appear which leads to the imbalance. However, this problem could be solved by introducing a special electromotor valve which would be placed at the beginning of the distribution system and control the accumulation of the system. To test this solution, a simulation model was created using Arena Simulation tool. Data for the simulation model are collected by the natural gas distributor and consist of natural gas consumption and nomination values for one measuring-reduction station on the hourly basis. Thus, the final dataset includes 8.754 records. The separate As-Is and To-Be models for seven (summer) months were made and the results were compared. The simulation experiment shows that the positive rebalancing energy would be reduced by 32%, and the negative one by 34%. The created model can serve as a good initial step for the analysis of the justification of investment in the implementation of a technical solution that would manage the accumulation of the distribution system.

MiStay: Web-based hourly hotel accommodation service

This case focuses on initiatives taken by the Indian travel tech company MiStay during the COVID-19 pandemic and describes the unique strategies that forced its presence into the accommodation industry of India. The travel tech company acts as a liaison between hotels and travellers. With its online booking system, travellers can book rooms on an hourly basis. This discussion is based on the various hiccups the company has faced along with how the new idea of flexible room booking systems benefit all relevant parties. Here, the focus is on the change of the century-old hotel booking system, resulting in the creation of a new era for accommodation businesses. The changing perception caused by this paradigm shift in hotel booking systems is going to impact the hospitality industry as MiStay may face many potential competitors in the future.

Forecasting Bitcoin price using time opinion mining and bi-directional GRU

Bitcoin is an innovative decentralized digital currency without intermediaries. Bitcoin price prediction is a demanding need in the present situation. This paper makes an investigation on the Bitcoin price forecast with a Bi-directional Gated Recurrent Unit (GRU) time series method, combined with opinion mining based on Twitter and Reddit feeds. An hourly basis sentimental analysis through the implementation of Natural Language Processing presents a positive impact of sentimental analysis on the Bitcoin price prediction. For prediction, RNN, long-short memory, GRU has been utilized. Unidirectional and Bi-directional versions of all three networks with and without sentimental analysis were implemented for comparison. Of all the techniques implemented Bi-directional GRU along with sentimental analysis gives a minimum RMSE and Minimum absolute percentage error of 1108.33 and 7.384%. Thus, the framework including Bi-Directional GRU along with Sentimental Analysis provides better results than the State-of-art methods.

Robust Antibody Responses to the BNT162b2 mRNA Vaccine Occur Within a Week After the First Dose in Previously Infected Individuals and After the Second Dose in Uninfected Individuals

BackgroundVaccines against severe acute respiratory syndrome coronavirus 2 can trigger acquired immunity in infection-naïve individuals and offer a path toward ending the coronavirus disease pandemic that began in 2019. However, the kinetics of early antibody responses in vaccinated individuals remain poorly understood.MethodWe followed BNT162b2 mRNA-vaccinated health care workers (HCWs, N=108) including 103 infection-naïve and five previously infected individuals. A total of 763 blood samples were collected weekly or hourly basis before and after vaccination. Serological analysis of anti-spike and anti-nucleocapsid antibodies was performed.ResultsSeroconversion occurred in all infection-naïve HCWs 3 weeks after the first dose (just before the second vaccination) and a marked boosting effect was observed at 4 weeks (1 week after the second dose). Among previously infected HCWs with pre-existing antibodies against the spike protein, a remarkable boosting effect was observed during the first week after vaccination, and a further increase in antibody titres was observed after the second dose. In one previously infected patient, daily blood sampling was conducted. Antibody titres began to increase 96 hours (4 days) after the first dose.ConclusionThe BNT162b2 mRNA vaccine remarkably enhanced antibody responses after the second dose in infection-naïve individuals and after the first dose in previously infected HCWs of all ages and genders. Antibody titres decreased slightly after the 5th week post-vaccination. The robust boosting effect of immunisation suggests that increased antibody titres following exposure to the virus may restrict viral replication, prolong the incubation period, or lessen the severity of disease.

A New Computational Tool for the Development of Advanced Exergy Analysis and LCA on Single Effect LiBr–H2O Solar Absorption Refrigeration System

A single effect LiBr–H2O absorption refrigeration system coupled with a solar collector and a storage tank was studied to develop an assessment tool using the built-in App Designer in MATLAB®. The model is developed using balances of mass, energy, and species conservation in the components of the absorption cooling system, taking into account the effect of external streams through temperature and pressure drop. The whole system, coupled with the solar energy harvesting arrangement, is modeled for 24 h of operation with changes on an hourly basis based on ambient temperature, cooling system load demand, and hourly solar irradiation, which is measured and recorded by national weather institutes sources. Test through simulations and validation procedures are carried out with acknowledged scientific articles. These show 2.65% of maximum relative error on the energy analysis with respect to cited authors. The environmental conditions used in the study were evaluated in Barranquilla, Colombia, with datasets of the Institute of Hydrology, Meteorology and Environmental Studies (IDEAM), considering multiannual average hourly basis solar irradiation. This allowed the authors to obtain the behavior of the surface temperature of the water in the tank, COP, and exergy efficiency of the system. The simulations also stated the generator as the biggest source of irreversibility with around 45.53% of total exergy destruction in the inner cycle without considering the solar array, in which case the solar array would present the most exergy destruction.

Evaluation of occupant's adaptive thermal comfort behaviour in naturally ventilated courtyard houses

PurposeIn vernacular buildings, many climatic and passive solutions have been used to create indoor thermal comfort. Seasonal occupant movement is an example of a traditional response to increasing thermal comfort. This article investigates the influence of these user behaviours on thermal comfort in courtyard houses.Design/methodology/approachParametric models of three different scenarios of courtyard houses are simulated. The courtyard houses are located in Shiraz, Iran, and share the same orientation and construction materials. To enhance the accuracy of the study, the indoor adaptive thermal comfort (ATC) analysis is performed with three different window-to-wall ratios (WWR) of 25, 50 and 75%. The ACT analysis is performed on an hourly basis for summer and winter scenarios.FindingsThe results demonstrate that the indoor ATC is 8.3% higher in winter than in the summer in the seasonal zones. During the summer, the amount of ATC is relatively sustained in all zones. Unlike common beliefs, seasonal movement can enhance the ATC, especially during winter, specifically in the northern part of the courtyard. In northern zones, the seasonal movement of occupants improves the indoor ATC from 10.1 to 23.7%, and in southern zones, the improvement is from 2.2 to 4.8%.Originality/valueThis research presents a new numerical investigation into occupants' seasonal movements in courtyard houses during summer and winter. It provides a precise pattern to show how much this seasonal movement can affect the habitant's ATC.

Outbreak of Catopsilia pyranthe L. on Senna (Cassia angustifolia Vahl) and Migration in Western Arid Region of India

Background: Cassia angustifolia Vahl, senna, known for medicinal properties belongs to family fabacea is a hardy plant, suitable for saline and rainfed conditions serving as a host for caterpillars of Catopsilia pyranthe L. butterflies suffering up to 90 per cent defoliation. An attempt was made to record butterfly migrations due to an outbreak of the lepidopteron pest on senna which is the first report on butterfly migration in western arid region.Methods: Surveys made in different districts for accurate quantification of butterflies passing within 5 minute through a 10 meter wide strip. For diurnal pattern, observations were taken on hourly basis. Correlation of butterfly density with weather parameters was worked out.Result: Migration was mainly in South West direction in a steady line connecting Jaisalmer, Jodhpur, Pali, Sirohi and Ajmer. The highest density (1360 butterflies/10m/5 minute) accounting for 16,320.0 butterflies/10m/hour and 97,920.0 butterflies/10m/day recorded in Keru (Jodhpur) representing bell shape curve of diurnal movement with a maximum activity between 12.00 noon and 1.00 PM.