Drip irrigation using a PLC based adaptive irrigation system

Most of the water used by man goes to irrigation. A major part of this water is used to irrigate small plots where it is not feasible to implement full-scale Evapotranspiration based irrigation controllers. During the growth season crop water needs do not remain constant and varies depending on the canopy, growth stage and climate conditions such as temperature, wind, relative humidity and solar radiation. Thus, it is necessary to find an economic irrigation controller that can adapt the daily water application to the plant needs. The dramatic development of Programmable Logic Controllers, PLCs, and their rather affordable price has made it possible to use them as stand-alone irrigation controllers. In this paper a PLC is used to adapt the daily irrigation amount to actual ETc, using a Hargreaves-Samani type equation. This equation only requires temperature values to calculate Evapotranspiration. Once the ETc is calculated, then the PLC manages the irrigation according to the characteristics of the field, the irrigation equipment and the growth stage of the crop. First year results are very encouraging and indicate a 12% saving in irrigation water. It was also found that heat flux form the soil can influence canopy temperature.The development of this study was funded by the Fundação para a Ciência e a Tecnologia (FCT) research project PTDC/AGR-AAM/81271/2006: “Desenvolvimento dum controlador de rega adaptativo, autónomo e automático”

Desenvolvimento dum sistema de rega automático, autónomo e adaptativo – estudo comparativo de cinco métodos para o cálculo da ETo

Para efeitos de desenvolvimento dum sistema de rega automático, são estudados e calibrados cinco métodos de cálculo de Evapotranspiração de referência (Priestley-Taylor, Makkink, Hargreaves, Turc, Jensen-Haise) utilizando apenas os parâmetros climáticos temperatura, T, e radiação solar, Rs. O estudo envolve o cálculo da Evapotranspiração para todos os dias do ano hidrológico 2005/06 e a sua comparação com o método de Penman-Monteith. A estação escolhida para o estudo é a estação de Divor. Nas condições do estudo (Sul da Península Ibérica) os melhores resultados são obtidos com os métodos de Priestley-Taylor e Jensen-Haise. São apresentados os coeficientes de calibração para todos os cinco métodos para a zona do estudo, por forma a aproximar ao máximo os resultados aos obtidos pelo método de referência.In order to develop an automatic irrigation system, a set of five different methods for calculating reference evapotranspiration are studied and calibrated (Priestley-Taylor, Makkink, Hargreaves, Turc, Jensen-Haise). These methods use temperature, T, and solar radiation, Rs, to calculate evapotranspiration. Evapotranspiration is calculated for all the days of the 2005/06 hidrological year at the Divor meteorological station. The results are compared to, and calibrated against, the Penman-Monteith method. The best results are obtained by the Priestley-Taylor and Jensen-Haise methods. Calibration coefficients are also calculated for all five methods, so that the results can be as close as possible to those produced by the Penman-Monteith method

Optimizing rain harvesting for Mediterranean climate

Most of the urban landscaped areas are watered with drinking water from the city utility. This represents a waste of energy used to pump the water all the way into urban areas, as well as a waste of chemicals and energy used to purify the water for human consumption. This paper analysis the feasibility of harvesting rainwater over buildings in Mediterranean climate, and storing them, for use in irrigation. The results indicate that a typical house can annually save between 3000 and 11000 l of water through rain harvesting. A simulation model is elaborated that can calculate optimize the relation between catchment area, irrigated area and tank size, based on daily rainfall and evapotranspiration of a five year period

Water saving with a PLC based adaptive irrigation system

Irrigation is presently the main user of world´s fresh water. Most of it goes to irrigating small plots where it is not feasible to implement full-scale Evapotranspiration based irrigation controllers. The dramatic development of Programmable Logic Controllers, PLCs, and their rather affordable price has made it possible to use them as stand-alone irrigation controllers. In this paper a PLC is used to adapt the daily irrigation amount to actual ETc, using a Hargreaves-Samani type equation. Once the ETc is calculated, then the PLC manages the irrigation according to the specifications given by the farmer. First year results indicate an 8% saving in irrigation water

Stability and enzymatic studies with omeprazole: hydroxypropyl-β-cyclodextrin

The original publication is available at www.springerlink.com. A publicação original está disponível em www.springerlink.comOmeprazole (OME) exhibits low stability to light, heat and humidity. In stress conditions OME stability should improve under inclusion complex form with hydroxypropyl-b-cyclodextrin (HPbCD). Stability of OME, its physical mixture (PM) with HPbCD and OME:HPbCD inclusion complex was assessed during 60 days. The inclusion complexes were prepared by kneading and freezedrying techniques and characterized by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). A molecular modelling was also held to predict the most probable tridimensional conformation of inclusion complex OME:HPbCD. The inhibitory activity of free and complexed OME on selected enzymes, namely, papain (protease model of the proton pump) and acetylcholinesterase (enzyme present in cholinergic neurons and also involved in Alzheimer’s disease) was compared. The results obtained show that HPbCD do not protect against OME degradation, in any prepared powder, in the presence of light, heat and humidity. This may indicate that the reactive group of OME is not included in the HPbCD cavity. This fact is supported by molecular modelling data, which demonstrated that 2-pyridylmethyl group of OME is not included into the cyclodextrin cavity. In relation to enzymatic assays it was observed that free OME and OME in the binary systems showed identical inhibitory activity on papain and acethylcolinesterase, concluding that HPbCD do not affect OME activity on these two enzymes

Bioactivity studies and chemical profile of the antidiabetic plant Genista tenera

Aim of the study: Genista tenera is a plant endemic to the island of Madeira and is used in folk medicine to control diabetes. In the present work we evaluate the antihyperglycaemic activity of its n-butanol extract and determine its chromatographic profile. In addition, this extract, the ethyl acetate and diethyl ether plant extracts were studied in order to assess the plant antioxidant and acetylcholinesterase inhibitory activities, as well as its cyto- and genotoxicities. Materials and methods: HPLC-DAD-ESI-MS was used to analyze the flavonoid profile of the n-butanol extract. The antihyperglycaemic activity of this extract was performed over streptozotocin induced diabetic Wistar rats (200mg/kg, bw/day), for 15 days. Antioxidant activity (DPPH assay) and acetylcholinesterase inhibitory effect (Ellman method) were also performed. Acute cytotoxicity and genotoxicity were assessed by proliferative index quantification and the short-term chromosomal aberration technique, after exposure of lymphocytes to the extracts. Results and conclusions: The n-butanol extract, where 21 monoglycosyl and 12 diglycosyl flavonoids were detected, significantly lowered blood glucose levels, bringing them to normal values after 15 days of treatment. The best radical scavenging activity was observed for the ethyl acetate extract (48.7% at 139.1μg/mL), which was also the most effective one at the minimal concentration tested. The highest acetylcholinesterase inhibitory activity (77.0% at 70. 0μg/mL) was also obtained with the ethyl acetate extract. In vitro toxicity studies showed no evidence for acute cytotoxicity or genotoxicity. This is the first report on antidiabetic activity of genus Genista.MCES, FCT, British Council; BBSRC and Merck, Sharp & Dohm

Mortality and pulmonary complications in patients undergoing surgery with perioperative sars-cov-2 infection: An international cohort study

Background The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (740%) had emergency surgery and 280 (248%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (261%) patients. 30-day mortality was 238% (268 of 1128). Pulmonary complications occurred in 577 (512%) of 1128 patients; 30-day mortality in these patients was 380% (219 of 577), accounting for 817% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 175 [95% CI 128-240], p<00001), age 70 years or older versus younger than 70 years (230 [165-322], p<00001), American Society of Anesthesiologists grades 3-5 versus grades 1-2 (235 [157-353], p<00001), malignant versus benign or obstetric diagnosis (155 [101-239], p=0046), emergency versus elective surgery (167 [106-263], p=0026), and major versus minor surgery (152 [101-231], p=0047). Interpretation Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Morphology of the Faial Island shelf (Azores): the interplay between volcanic, erosional, depositional, tectonic and mass-wasting processes

[1] The extents of volcanic island shelves result from surf erosion, which enlarges them, and volcanic progradation, which reduces them. However, mass‐wasting, tectonics and sediment deposition also contribute to their morphology. In order to assess the relative significance of these various processes, we have mapped in detail Faial Island's shelf in the Azores archipelago based on interpretation of geophysical and geological data. The nearshore substrates of the island, down to 30–50 m depth, are rocky and covered by volcaniclastic boulder deposits formed by surf action on now‐submerged lava flows. Below those depths, sandy and gravel volcaniclastic beds dominate, building clinoforms up to the shelf edge. In some sectors of the coast, prograding lava has narrowed the shelf, but, in contrast to nearby Pico Island, we find fewer submarine‐emplaced lavas on the shelf. In this island, we interpret the distance between the coastline and the shelf edge as almost entirely a result of a straightforward competition between surf erosion and lava progradation, in which erosion dominates. Therefore shelf width can be used as a proxy for coastline age as well as for wave energy exposure. The stratigraphy of shelf deposits in boomer seismic data is examined in detail to assess the roles of different sediment sources, accommodation space and wave exposure in creating these deposits. We also show evidence of mass‐wasting at the shelf edge and discuss the possible origins of slope instability. Finally, we discuss the contributing role of tectonics for the development of the shelf.publishe

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research