Authors:J.K. Odusote, A.A. Adeleke, P.P. Ikubanni, O.S. Ayanda, J.M. Abdul, and R.A. Yahya
corrosion, a passive oxide adherent film is usually formed in various environments. The amphoteric nature of the oxide film causes it to dissolve significantly when the metal is placed in a high concentration of acidic or basic media [ 5 ]. After the oxide
Authors:Ezekiel Folorunso Sodiya and Folasegun Anthony Dawodu
of inhibitory secondary metabolites but lower concentrations of phytochemicals as in the case of Jatropha curcas [ 7 , 8 ] determined qualitatively was synergized with another extract of fewer phytoconstituents but of higher concentration
field predictions using different turbulence models, whereas combustion characteristics (e.g., temperature and gas concentration) were predicted reasonably well by all models.
One of the turbulence-chemistry interaction models most used with
Authors:Ikram Abarkan, Abdellatif Khamlichi, and Rabee Shamass
such as groove, fillet, and holes (i.e., notches) that, due to the phenomenon of stress concentration, can produce extensive plastic deformation even at applied stresses lower than the elastic limit. Besides, the presence of notches induce a multiaxial
Detailed analysis of household generated greywater (GW) samples is an essential task for the design of treatment systems before reuse. In this paper modern analytical methods will be discussed, which were applied to determine the ionic and elemental concentration of different GW samples. Ion chromatography (IC) and Microwave plasma atomic emission spectrometry (MP-AES) methods were used to spoor the composition of GW samples. It was shown that from the IC results and from calculated parameters (Na ee% and SAR) the application of raw or treated GW flows for irrigation is controlled. According to the elemental concentration, GW samples from laundry/kitchen sink and dishwasher proved to be the most contaminated compared to drinking water, while the concentration of the measured elements did not elevate as significantly in GW samples from shower/bathtub.
The aim of this article is to examine the effect of temperature, humidity, air velocity and CO2 concentration regarding the human behaviour in indoor environment with natural ventilation, i.e. without a ventilation device, or where there is forced ventilation or an air conditioning.
Authors:Gy. Lakatos, I. Csatári, T. Igaz, I. Gyulai, and I. Mészáros
This paper presents the results of the floristical examinations performed in the units of a former secondary sedimentation pond system in Hungary. The outcome of analyses on the chromium content of the plants is discussed. Beside the chemical analyses, observations on the plants, the characterization of the ecological state of plant stands adapted to heavy metal load. Results of the elemental analysis for heavy metals revealed that none of the plants constituting the natural vegetation can be treated as hyperaccumulator plant. A green cover and the detoxification process of Cr(VI) by plants is suggested to be more important than the present extensive phytoextraction procedure. It can be stated that due to the disturbance our investigated area has diverse vegetation, in addition these plants can tolerate a high concentration of heavy metals, and they are able to take up them.
It is a prime aim to ensure a suitable comfort level in case of office buildings. The productivity of office employees is directly influenced by the comfort. Thermal discomfort and poor indoor air quality deteriorate the intensity and quality of human work. We investigated the comfort in office buildings with on-site measurements during the summer season. The office buildings were operating with different HVAC (Heating, Ventilating and Air-Conditioning) systems: ducted fan-coil with suspended ceiling, installation, non-ducted fan-coil with floor-mounted installation, active chilled beam with fresh air supply.
We evaluated the thermal comfort under PMV (Predicted Mean Vote), PPD (Predicted Percentage of Dissatisfied), the local discomfort based on DR (Draught Rate) and the IAQ (Indoor Air Quality) based on carbon dioxide concentration. The comfort measurements were evaluated. The measurements were evaluated with scientific research methods, comfort categories based on the requirements of CR 1752. The results of this comparison were presented in this article.
Authors:Tamás Pándics, Eszter Róka, Bernadett Khayer, Zoltán Kis, Luca Bella Kovács, Nóra Magyar, Tibor Málnási, Orsolya Oravecz, Bernadett Pályi, Eszter Schuler, and Márta Vargha
Összefoglaló. A szennyvízalapú epidemiológia módszere a jelenlegi
világjárványban egyre inkább előtérbe kerül. Mivel a szennyvízhálózatot szinte
mindenki használja, ezzel a módszerrel gyorsan és olcsón lehet reprezentatív
egészségügyi információhoz jutni, az így keletkező adatok pedig támogatást és
visszajelzést nyújthatnak a döntéshozatalban. A Nemzeti Népegészségügyi Központ
2020 júniusa óta működteti a COVID–19 előrejelző rendszert. A mintavételek
hetente történnek Budapest három szennyvíztisztítójából, valamint a
megyeszékhelyekről. A kapott adatok hazánkban is előrejelzik az esetszám
alakulását, az eredmények gyors kommunikációja pedig lehetővé teszi a
járványhelyzetre történő felkészülést. A szennyvízalapú epidemiológia
alkalmazása a jövőben más területeken is megfontolandó hazánkban is.
Summary. Wastewater based epidemiology (WBE) is an emerging method
in the current COVID-19 pandemic. Since almost everyone uses the sewerage
system, wastewater is technically a composite sample representing the entire
population of the area serviced by a wastewater plant. This community sample
contains pathogens and compounds excreted by the human body through feces or
urine, and can be used to obtain information on the health status of the
community. It was successfully used previously for confirming the eradication of
poliovirus and tracking legal and illegal drug consumption.
The etiological agent of COVID-19, the SARS-CoV-2 virus is an enveloped, single
strand RNA coronavirus. Although it is a respiratory virus, it is also shed in
feces both in symptomatic and asymptomatic infections. Wastewater therefore can
be used to estimate outbreak trends and support outbreak management.
Wastewater monitoring efforts in Hungary started in June 2020, first in Budapest,
then gradually extended to a national surveillance system. Weekly samples are
collected in the three wastewater treatment plants servicing Budapest, and from
every county seat. The analyzed 22 samples represent approximately 40 % of the
population. Raw sewage samples are centrifuged to remove the debris and
concentrated by membrane ultrafiltration. RNA is extracted from the concentrate
and SARS-CoV-2 is quantified by RT-qPCR. Results are normalized to
Enterococcus counts to correct for the bias of dilution
The first results in June reflected the decline of the first wave of the
outbreak. During the summer, viral RNA concentrations were low, mainly below the
limit of detection. The increase of RNA in the sewage preceded the resurge of
cases by 2 weeks. Trends of viral concentration followed the same pattern as the
number of infections in the second and third wave. SARS-CoV in sewage shows
statistically significant association with the number of new cases in the
following weeks, thus it can be used as an early warning system.
Results are communicated weekly to the governance board responsible for outbreak
management, or more frequently in case of outstanding results or when it is
necessary for decision support. Weekly information is also made available to the
public. To inform the public, concentration categories (low, medium, elevated
and high) were defined, representing orders of magnitude of the viral RNA
concentration. Trends (increasing, stagnating or decreasing) are also
The establishment of a long-term wastewater surveillance system would provide an
opportunity for early recognition of future emerging infections, tracking
seasonal influenza, drug use or even the detection of certain bioterror attacks.
It would be an important addition to maintaining the health and safety of the