Promoting urban rainwater harvesting in Dhaka, Bangladesh

With rapid population growth and Unplanned urbanisation water has turn into a scare resource in Dhaka city. This city will visage a severe water crisis to meet its increasing demand in near future. Present water supply depend on 87% groundwater extraction with groundwater table depletion at a rate of 2.81meter/year. No management initiatives revealed to protect groundwater recharging. WaterAid follows an approach to reach academics, researchers, urban planners, civil engineers, architects and policy makers for promoting rainwater harvesting through collective action. As immediate result, 4 universities adopted contents of rain water harvesting in course curricula, initiated 4 piloting researches by different institutions, urban planners and architects are engaged in construction designing to adopt rainwater harvesting, and changes adopted in the national building codes.. This paper denotes WaterAid initiatives and sign of impact to promote urban rainwater harvesting in Dhaka city

Healthy-home approach: lasting changes in hygiene behaviour in rural Bangladesh

NGOs have been struggling for over a decade in Bangladesh to bring visible changes in hygiene behaviour at the community level. However, few of these initiatives focus specifically on promoting hygiene behaviour at the practice level. Providing hygiene messages following traditional approaches achieves numeric figures, but often fails to bring real changes on the ground. WaterAid Bangladesh piloted an approach called “healthy home” under its rural programme, which encourages communities to promote safe water and sanitation through recognition and owners of “healthy home”. A wide range of stakeholders engage in the process led by local government institutions (LGIs).. Over an eight months period of time, more than 80% household owners have been awarded as healthy-home promoters against targeted numbers, and have been declared so by LGIs publicly. Recognition, dignity and ownership work as motivating factors in this process, which could be capitalised for greater achievement in other programmes

WASH 5 Star approach: addressing hygiene behaviour in schools of rural Bangladesh

Every child has basic rights to safe drinking water, sanitation and hygiene (WASH). School are essential institutions to children’s welfare, and a place where lifelong behaviours are inculcated. The National Hygiene Baseline Survey [1] and recent WASH bottleneck analysis of Bangladesh [2] reflected the worrying state of hygiene behaviour in schools. WaterAid Bangladesh has developed an approach called ‘WASH 5 Star’ based on the five behavioural domains articulated in the National Hygiene Promotion Strategy (NHPS) 2012 in Bangladesh [3] to raise awareness at the individual, household and institutional level on proper hygiene practices . The WASH 5 Star approach was introduced in 2500 schools in rural Bangladesh and yielded encouraging results within a short span of time. This approach can to be introduced at a large scale to achieve wider health benefits

Revisiting Borylanilines: Unique Solid-State Structures and Insight into Photophysical Properties

The structure and photophysical properties of two known borylanilines, 4-(dimesitylboryl)­aniline (<b>1</b>) and 4-(dimesitylboryl)-3,5-dimethylaniline (<b>2</b>), have been investigated. <b>1</b> and <b>2</b> have similar donor and acceptor centers but differ in their molecular conformations. Compounds <b>1</b> and <b>2</b> have been structurally characterized, and they exhibit a rare form of intermolecular N–H- - -π electrostatic interactions. The structure and photophysical properties of <b>1</b> and <b>2</b> are discussed in the context of computational results

Going beyond Red with a Tri- and Tetracoordinate Boron Conjugate: Intriguing Near-IR Optical Properties and Applications in Anion Sensing

The design and synthesis of a new tri- and tetracoordinate boron conjugate is reported. The conjugate shows broad near-IR emission (∼625–850 nm) and is found to be a selective colorimetric and ratiometric sensor for fluoride ions

Multichannel-Emissive V‑Shaped Boryl-BODIPY Dyads: Synthesis, Structure, and Remarkably Diverse Response toward Fluoride

Three new V-shaped boryl-BODIPY dyads (<b>1–3</b>) were synthesized and structurally characterized. Compounds <b>1–3</b> are structurally close molecular siblings differing only in the number of methyl substituents on the BODIPY moiety that were found to play a major role in determining their photophysical behavior. The dyads show rare forms of multiple-channel emission characteristics arising from different extents of electronic energy transfer (EET) processes between the two covalently linked fluorescent chromophores (borane and BODIPY units). Insights into the origin and nature of their emission behavior were gained from comparison with closely related model molecular systems and related photophysical investigations. Because of the presence of the Lewis acidic triarylborane moiety, the dyads function as highly selective and sensitive fluoride sensors with vastly different response behaviors. When fluoride binds to the tricoordinate borane center, dyad <b>1</b> shows gradual quenching of its BODIPY-dominated emission due to the ceasing of the (borane to BODIPY) EET process. Dyad <b>2</b> shows a ratiometric fluorescence response for fluoride ions. Dyad <b>3</b> forms fluoride-induced nanoaggregates that result in fast and effective quenching of its fluorescence intensity just for ∼0.3 ppm of analyte (i.e., 0.1 equiv ≡ 0.26 ppm of fluoride). The small structural alterations in these three structurally close dyads (<b>1–3</b>) result in exceptionally versatile and unique photophysical behaviors and remarkably diverse responses toward a single analyte, i.e., fluoride ion

Dual Binding Site Assisted Chromogenic and Fluorogenic Recognition and Discrimination of Fluoride and Cyanide by a Peripherally Borylated Metalloporphyrin: Overcoming Anion Interference in Organoboron Based Sensors

Peripherally triarylborane decorated porphyrin (<b>2</b>) and its Zn­(II) complex (<b>3</b>) have been synthesized. Compound <b>3</b> contains of two different Lewis acidic binding sites (Zn­(II) and boron center). Unlike all previously known triarylborane based sensors, the optical responses of <b>3</b> toward fluoride and cyanide are distinctively different, thus enabling the discrimination of these two interfering anions. Metalloporphyrin <b>3</b> shows a multiple channel fluorogenic response toward fluoride and cyanide and also a selective visual colorimetric response toward cyanide. By comparison with model systems and from detailed photophysical studies on <b>2</b> and <b>3</b>, we conclude that the preferential binding of fluoride occurs at the peripheral borane moieties resulting in the cessation of the EET (electronic energy transfer) process from borane to porphyrin core and with negligible negetive cooperative effects. On the other hand, cyanide binding occurs at the Zn­(II) core leading to drastic changes in its absorption behavior which can be followed by the naked eye. Such changes are not observed when the boryl substituent is absent (e.g., Zn-TPP and TPP). Compounds <b>2</b> and <b>3</b> were also found to be capable of extracting fluoride from aqueous medium

Multichannel-Emissive V‑Shaped Boryl-BODIPY Dyads: Synthesis, Structure, and Remarkably Diverse Response toward Fluoride

Three new V-shaped boryl-BODIPY dyads (<b>1–3</b>) were synthesized and structurally characterized. Compounds <b>1–3</b> are structurally close molecular siblings differing only in the number of methyl substituents on the BODIPY moiety that were found to play a major role in determining their photophysical behavior. The dyads show rare forms of multiple-channel emission characteristics arising from different extents of electronic energy transfer (EET) processes between the two covalently linked fluorescent chromophores (borane and BODIPY units). Insights into the origin and nature of their emission behavior were gained from comparison with closely related model molecular systems and related photophysical investigations. Because of the presence of the Lewis acidic triarylborane moiety, the dyads function as highly selective and sensitive fluoride sensors with vastly different response behaviors. When fluoride binds to the tricoordinate borane center, dyad <b>1</b> shows gradual quenching of its BODIPY-dominated emission due to the ceasing of the (borane to BODIPY) EET process. Dyad <b>2</b> shows a ratiometric fluorescence response for fluoride ions. Dyad <b>3</b> forms fluoride-induced nanoaggregates that result in fast and effective quenching of its fluorescence intensity just for ∼0.3 ppm of analyte (i.e., 0.1 equiv ≡ 0.26 ppm of fluoride). The small structural alterations in these three structurally close dyads (<b>1–3</b>) result in exceptionally versatile and unique photophysical behaviors and remarkably diverse responses toward a single analyte, i.e., fluoride ion

Highly Transparent Crosslinkable Radical Copolymer Thin Film as the Ion Storage Layer in Organic Electrochromic Devices

A highly transparent crosslinkable thin film made of the radical polymer poly­(2,2,6,6-tetramethyl-4-piperidinyloxy methacrylate)-<i>co</i>-(4-benzoylphenyl methacrylate) (PTMA-<i>co</i>-BP) has been developed as the ion storage layer in electrochromic devices (ECDs). After photo-crosslinking, the dissolution of PTMA-<i>co</i>-BP in electrolytes was mitigated, which results in an enhanced electrochemical stability compared with the homopolymer PTMA thin film. Moreover, the redox capacity of PTMA-<i>co</i>-BP increased because of the formation of a crosslinked network. By matching the redox capacity of the PTMA-<i>co</i>-BP thin film and bis­(alkoxy)-substituted poly­(propylenedioxythiophene), the ECD achieved an optical contrast of 72% in a small potential window of 2.55 V (i.e., switching between +1.2 and −1.35 V), and it was cycled up to 1800 cycles. The ECD showed an excellent optical memory as its transmittance decayed by less than 3% in both the colored and bleached states while operating for over 30 min under open-circuit conditions. Use of crosslinkable radical polymers as the transparent ion storage layer opens up a new venue for the fabrication of transmissive-mode organic ECDs