Libraries, as service-oriented organizations, are being guided on every aspect of their operation by local and international standards. In the Philippines, public libraries are expected to adhere to the stipulations of the ...

Polyaspartic acid (PASP), a well-known green scale inhibitor for industrial water treatment, might be decomposed with prolonged duration, and its anti-scaling performance against CaCO<small>₃</small> and CaSO<small>₄</small> is diminished at a low concentration (&lt;10 mg L<small>⁻¹</small>) and a high temperature. With semi-ethylenediaminetetraacetic acid (EDTA) tetrasodium salt as the mimicking model, novel phosphorus-free PASP-capped 2-aminoethylamino acid (PASP–ED<small>₂</small>A) containing side chains bearing multi-functional groups is rationally designed and successfully prepared via the ring-opening reaction of cheap poly(succinimide) under mild reaction conditions with the assistance of readily available 2-aminoethyl amino acid. The static scale inhibition method is used to evaluate the scale inhibition performance of the as-synthesized PASP derivative. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy are utilized to monitor the crystallization process of calcium carbonate and calcium sulfate scales, and density functional theory calculations are conducted to shed light on the relationship between the molecular structure and scale inhibition mechanism of PASP–ED<small>₂</small>A. Results show that the as-prepared PASP–ED<small>₂</small>A shows better scale inhibition performance for CaCO<small>₃</small> and CaSO<small>₄</small> than PASP with a low concentration, a high temperature, and an extended duration. Particularly, PASP–ED<small>₂</small>A with a concentration of 10 mg L<small>⁻¹</small> exhibits the best scale inhibition performance for CaCO<small>₃</small>; its scale inhibition capacity is about two times as much as that of PASP. The reason lies in that the coordination atoms in the molecular structure of PASP–ED<small>₂</small>A can chelate with Ca<small>²⁺</small> to inhibit the combination of Ca<small>²⁺</small> with anions and prevent the generation of CaCO<small>₃</small> and CaSO<small>₄</small> scales. The PASP–ED<small>₂</small>A derivative can more efficiently retard the formation and growth of CaCO<small>₃</small> and CaSO<small>₄</small> crystal nuclei and exerts better inhibition performance against CaCO<small>₃</small> and CaSO<small>₄</small> scales than PASP....

Musical data mining covers a number of methodologies to successfully apply data mining techniques for music processing, drawing together a multidisciplinary array of top experts. The field of music data acquisition has ...

With the continuous improvement of China’s market economy, many listed companies enjoy the unlimited development opportunities brought by the market economy environment but are also threatened by various potential risks. ...

The emergence of computer network virtual experiment teaching provides the possibility to solve the limitations of hardware equipment and time for cultivating computer talents in colleges and universities. Although the ...

From the current social development situation, the economic development of various regions is very fast, and the rapid development of urbanization has also driven the development of the tourism industry. At present, the ...